Yellow Filter Research Articles

Adjusting to a sudden “aging” of the lens

Color perception is known to remain largely stable across the lifespan despite the pronounced changes in sensitivity from factors such as the progressive brunescence of the lens. However, the mechanisms and timescales controlling these compensatory adjustments are still poorly understood. In a series of experiments, we tracked adaptation in observers after introducing a sudden change in lens density by having observers wear glasses with yellow filters that approximated the average spectral transmittance of a 70-year-old lens. Individuals were young adults and wore the glasses for 5 days for 8 h per day while engaged in their normal activities. Achromatic settings were measured on a CRT before and after each daily exposure with the lenses on and off, and were preceded by 5 min of dark adaptation to control for short-term chromatic adaptation. During each day, there was a large shift in the white settings consistent with a partial compensation for the added lens density. However, there was little to no evidence of an afterimage at the end of each daily session, and participants’ perceptual nulls were roughly aligned with the nulls for short-term chromatic adaptation, suggesting a rapid renormalization when the lenses were removed. The long-term drift was also extinguished by brief exposure to a white adapting field. The results point to distinct timescales and potentially distinct mechanisms compensating for changes in the chromatic sensitivity of the observer.

Low-Cost Fluorescein Detection System for High-Grade Glioma Surgery

Intraoperative fluorescein detection has been used in the fields of vascular and oncologic neurosurgery since 1948. Modifications of the optics in order to enhance the fluorescence contrast under microscopic view have been developed by many authors. The industries, during the past 10 years, provided commercial high-cost optimized apparatuses. Reviewing the literature, we found that the prototypical techniques were definitely inexpensive but lacked reliability, reproducibility, and standard legal norms. We describe the developing of a fluorescein detection system that could be economic, simple, effective, and law abiding. We employed a commercial violet-blue filter designed for fluorescein excitation in endoscopic procedures and used commercial photographic yellow optical filters for fluorescence detection. All the instrumentation is cleared for clinical use, and its cost is up to 200 times lower than commercial apparatuses. Our results show a good distinction of fluorescein-stained structures, with overall acceptable operating light conditions.

Effect of yellow filter on visual acuity and contrast sensitivity under glare condition among different age groups

The aim of this study is to investigate the effect of yellow filter on visual acuity and contrast sensitivity under glare condition for various ages. A total of 60 subjects, aged 5-60years, with no ocular pathology and no previous surgery were assessed in this cross-sectional study. We divided subjects into six subgroups according to their ages, and the number of subjects in each group was 10: group 1, aged 5-10years; group 2, aged 11-20years; group 3, aged 21-30years; group 4, aged 31-40years; group 5, aged 41-50years; and group 6, aged 51-60years. Snellen visual acuity and Pelli Robson contrast sensitivity with and without glare and with the use of yellow filter under glare condition were determined. Data analysis was carried out using SPSS, version 20. Our results showed a significant reduction in contrast sensitivity under glare condition in all age groups (p=0.000), which improved significantly with the use of yellow filter (p=0.000). Although when data in different age groups were analyzed separately, this improvement was only significant in older subjects, aged 51-60years (p=0.007). No significant difference was found between Snellen visual acuity with and without glare (p=0.083), and also we found no yellow filter effect on visual acuity under glare condition. We conclude that yellow filter, which absorbs short wavelength, may provide significant contrast sensitivity benefits for individuals and influences older subjects more than younger ones.

Fluorescein sodium-guided surgery in cerebral lymphoma

ObjectivesGrowth and progress of primary central nervous lymphoma (PCNSL) severely disrupt the blood brain barrier (BBB). Such disruptions can be intraoperatively visualized by injecting fluorescein sodium (FL) and applying a YELLOW 560nm surgical microscope filter. Here, we report a small cohort of patients with PCNSL that mimicked high grade gliomas (HGG) or cerebral metastases (CM), who had been operated on with the use of FL. Patients and methodsRetrospectively, seven patients with PCNSL were identified, who had been operated on by means of microsurgery after intravenous FL injection. The surgical reports were screened for statements on the grade of fluorescent staining in the tumor area. One representative case was chosen to show the staining under white light as well as under filtered light at different distances to the tumor area. ResultsAll patients had shown bright and homogenous fluorescent staining of the tumor (n=7. 100%). No adverse effects had been observed. ConclusionSimilar to patients with HGG or CM, patients with PCNSL may benefit from use of FL and the dedicated YELLOW 560nm filter in open surgery.

Comparison of conjunctival staining between lissamine green and yellow filtered fluorescein sodium

ObjectiveTo compare conjunctival staining between lissamine green and fluorescein sodium using a yellow barrier filter. DesignRetrospective cross-sectional study. ParticipantsThirteen eyes of 13 patients with dry eyes. MethodsAll patients underwent ocular surface staining with fluorescein sodium and lissamine green. Ocular surface staining with fluorescein sodium was observed through slit-lamp examination under cobalt blue illumination and a yellow filter. Temporal (0–5) and nasal (0–5) conjunctival staining grade was separately graded according to the Oxford scheme. The contrast score was defined as the absolute difference between mean grey values of punctate staining and background. Conjunctival staining grade and contrast scores were compared between these 2 staining methods. ResultsThe sum of the conjunctival staining grade (0–10) for the nasal and temporal conjunctiva was 4.7 ± 2.5 for fluorescein sodium, which was significantly higher than that of lissamine green, 4.1 ± 2.5 (p = 0.005). The contrast score of temporal and nasal conjunctival staining was 34.6 ± 12.0 and 34.7 ± 10.3, respectively, for fluorescein sodium, which was also significantly greater than for lissamine green (23.4 ± 8.1 and 21.0 ± 9.0, respectively; p = 0.003 and p = 0.003, respectively). ConclusionsConjunctival staining with fluorescein sodium and a yellow filter seems to be more sensitive for the detection of conjunctival damage than lissamine green. Fluorescein staining with the yellow filter has the advantage of simultaneous observation of both corneal and conjunctival damage in patients with dry eye without the need for additional vital staining.

Low Vision Management in a Case of Stargardt's Disease

Background: By the WHO definition “a person with low vision is a one who has impairment of visual functioning even after treatment, surgery or standard refractive correction and has a visual acuity of less than 6/18 to light perception or a visual field of < 10⁰ from the point of fixation, in the better eye but who is potentially able to use vision for the planning and execution of a task.” Stargardt’s disease is one of the commonest inherited retinal disorders, with a prevalence of 1 in 10,000. It is inherited as an autosomal recessive trait [1,2]. Most cases present with central visual loss and there is typically macular atrophy and with yellow-white flecks at the posterior pole, which are at the level of the retinal pigment epithelium (RPE). Autofluorescence (AF) imaging and fluorescein angiography can be helpful in the confirming the diagnosis [3,4]. The age of onset is usually in the early teens, but there is wide variation, with a later age of onset being associated with a better visual prognosis [5,6]. Case: A 26 year old female presented to the low vision clinic of B.P. Koirala Lions Center for Ophthalmic Studies after final diagnosis of B/L Stargardt’s disease and her presenting visual acuity of 0.5 logMAR in RE and 0.56 logMAR in her LE. She had no previous history of any ocular pathology, trauma in the past. She had no history of any systemic illness known to her and no similar history of vision loss in other family members. Her visual acuity was decreasing since 8 years which was apparently well 8 years back. The anterior segment was within normal limits and on dilated fundus examination on mydriasis there was typical honeycomb appearance of the macular region. On cycloplegic retinoscopy there was final subjective prescription of -0.50 DC X 180 axis but no improvement in her visual acuity in her both eyes. Her near visual acuity was N12 at 33cm of working distance. With the spectacle clip on telescope (1.5X) her visual acuity improved to 0.20 logMAR. 54% yellow filter as spectacle was also prescribed and approach magnification was also taught. Finally the patient was managed with 1.5X spectacle clip on telescope for distance, bar magnifier (1.5X) for near and 54% yellow filter for management of photophobia. Conclusion: Stargardt’s disease can be managed properly with improvement in visual acuity for both near and distance with significant improvement in visual acuity for both near and distance with significant improvement in other visual functions with low vision devices.

Characterizations of Electrical and Optical Properties on Ferroelectric Photodiode of Barium Strontium Titanate (Ba0.5Sr0.5TiO3) Films Based on the Annealing Time Differences and its Development as Light Sensor on Satellite Technology

Photodiode of Ba0.5Sr0.5TiO3 (BST) film has successfully been created by growing BST on the surface of p-type Si (100) substrate with chemical solution deposition (CSD) method and spin coating technique at a speed of 3000rpm for 30seconds. BST films were made with concentration of 1M and annealing process at the temperature of 850°C for 8, 15, 22, and 29hours. Characterizations of electrical and optical properties of the films were then conducted. I-V characterization was conducted in dark and bright conditions with green, yellow, and red filters. The results showed that the films had photodiode characteristic. Characterizations of optical properties were the absorbance and the reflectance. The obtained absorbance curve showed that the most absorbed and reflected wavelengths were in the range of 400-500nm and 570-600nm respectively. Data of film reflectance can be used to calculate band gap energy (Eg). The electrical and optical properties indicate which the BST film has a prospect to be used as a light sensor on the satellite.

NI-16 * INTRA-OPERATIVE USE OF FLUORESCEIN FOR MALIGNANT GLIOMA RESECTION DIFFERENTIATES TUMOR FROM NORMAL BRAIN TISSUE BASED ON HISTOPATHOLOGIC ANALYSIS

OBJECTIVES: To determine whether the use of IV fluorescein during surgery for malignant glioma can reliably be used to differentiate between infiltrative tumor and normal brain tissue. BACKGROUND: Fluorescein sodium is a molecular compound with fluorescent capabilities between light wavelengths of 520-530nm, appearing yellow-green (1). Neurosurgical application of fluorescein has been studied primarily for increasing intra-operative visibility of malignant gliomas (1). The mechanism of action has been hypothesized to involve disruption of the blood brain barrier (BBB) (2). Cells in areas with disrupted BBB take up fluorescein with a sensitivity of 94% and specificity of 89% for high-grade gliomas (2). We performed histopathologic analysis on tissue obtained during fluorescein-guided tumor resections to evaluate the differences between fluorescent and non-fluorescent tissue. METHODS: Two adult patients with suspected high-grade gliomas underwent surgical resection. Prior to opening of the dura 3mg/kg of IV fluorescein was given. A Zeiss OPMI Pentero microscope (Carl Zeiss Meditech Inc.) with a yellow 560nm filter was used to visualize the tumor. At the tumor margins, tissue was identified as bright and dark and sent as separate specimens for histopathological analysis. RESULTS: Histological sections of specimens labeled bright contained infiltrating glioma with focal microvascular proliferation. Histological sections of specimens labeled dark contained gray matter and focal subcortical white matter with no high-grade glioma identified. Final grading for both patients was WHO Grade IV, glioblastoma. CONCLUSION: Intra-operative use of fluorescein in surgical resection of malignant gliomas can help to distinguish between infiltrating tumor and normal brain tissue based on histopathological analysis. Further evaluation of the utility of flurorescein during high and low-grade glioma surgery is necessary.

Visibility through Atmospheric Haze and Its Relation to Macular Pigment

A major factor limiting the visibility of distant targets is veiling attributed to atmospheric scattering, known commonly as haze. It has been suggested that yellow filters (in this case, the macular pigments, MPs) could selectively absorb this haze, thus extending visual range. This study is an empirical test of the visibility hypothesis. Twelve subjects had their full contrast sensitivity function (CSF) (represented by six spatial frequencies) assessed in the presence of two background conditions: simulated blue haze and short wave-deficient light. Contrast sensitivity at the peak of the CSF (7.5 cycles per degree) was measured in the presence of the same two backgrounds as the full CSF, with the addition of a broadband xenon background condition in a separate sample of 25 subjects. Simulated blue haze was found to uniformly reduce the CSF in the 12 subjects for whom the full CSF was assessed. Therefore, only the peak was measured in the larger sample of 25 subjects. Macular pigment density was significantly related to energy at threshold for both the haze and xenon backgrounds but not the short wave-deficient background. Thus, subjects with higher levels of MP could withstand more light before losing sight of the target. This result is consistent with previous modeling of the visibility hypothesis as well as visual range improvements seen when using an artificial MP filter.

Editorial: The fluorescein-guided technique

The extent of resection remains an important aspect of the management of high-grade gliomas. Over the past decade there have been numerous studies supporting the role of an aggressive resection for high-grade gliomas when it is safe. This overarching strategy has been emphasized by all major neuro-oncology societies throughout the world. Therefore, why is it that many patients continue to just have a biopsy or less aggressive resection of their highgrade gliomas? The principle reason lies in the inability of the surgeon to detect the extent of tumor during the course of the resection. In most circumstances surgeons utilize their experience with color and consistency as the hallmark to guide the tumor resection. Unfortunately, many neurosurgeons in this country continue not to use navigation to guide the extent of resection, and intraoperative imaging is seldom utilized due to the expense of this methodology. In recent years a randomized, prospective study (Phase III trial) involving fluorescence-guided surgery with 5-aminolevulinic acid (5-ALA) confirmed that if the intent is to do an aggressive or even complete resection, then it is more readily accomplished using fluorescenceguided surgery than surgery guided by white light alone under the microscope.2 However, in the United States 5-ALA is not approved by the FDA and only a few investigators are able to use it by holding their own investigational new drug exemption. At the same time, other dyes have been utilized to try to enhance the extent of resection, namely indocyanine green and fluorescein. The limitations of indocyanine green primarily lie in its ability to stain tissue under white light, and, similar to fluorescein, it leaks out of tissue during the course of resection because (like fluorescein) it is not specifically taken up by tumor cells. Thus, the reliability of this technique has been somewhat less than optimal since it relies on a disrupted blood-brain barrier, and although this is typical for high-grade gliomas, these dyes will leak out of tissue once it is cut during the course of the tumor removal. In this study the authors have been able to modify the timing of administration and use a specific YELLOW 560 module to make it easier to see the fluorescein without having to switch back and forth between white light and the filter apparatus on the microscope.1 By using this approach the authors were able to very nicely facilitate a more aggressive extent of resection with a high degree of specificity and sensitivity in terms of comparison to histological margins and the finding of fluorescence. It appears that the use of the specific yellow filter on the microscope also leads to better accuracy in terms of identifying tumor and can also result in a reduction of the fluorescein dosage. Thus, although this is a very small series of patients, it is clear that the use of intravenous fluorescein during the surgical removal of high-grade gliomas with the specific yellow filter may be a very reasonable, safe, and inexpensive way to achieve what is essential for patients with this disease—namely an aggressive, if not, complete, resection. Obviously, it is critical to proceed with a study that incorporates a control population using navigation alone or even in comparison with 5-ALA, and eventually it will be necessary to prove the utility of this technique with a prospective, randomized Phase III trial. That said, the authors are on the right track, and this is an exciting advance in the field of surgical neuro-oncology. (http://thejns.org/doi/abs/10.3171/2013.11.FOCUS13535)

The covert world of fish biofluorescence: a phylogenetically widespread and phenotypically variable phenomenon.

The discovery of fluorescent proteins has revolutionized experimental biology. Whereas the majority of fluorescent proteins have been identified from cnidarians, recently several fluorescent proteins have been isolated across the animal tree of life. Here we show that biofluorescence is not only phylogenetically widespread, but is also phenotypically variable across both cartilaginous and bony fishes, highlighting its evolutionary history and the possibility for discovery of numerous novel fluorescent proteins. Fish biofluorescence is especially common and morphologically variable in cryptically patterned coral-reef lineages. We identified 16 orders, 50 families, 105 genera, and more than 180 species of biofluorescent fishes. We have also reconstructed our current understanding of the phylogenetic distribution of biofluorescence for ray-finned fishes. The presence of yellow long-pass intraocular filters in many biofluorescent fish lineages and the substantive color vision capabilities of coral-reef fishes suggest that they are capable of detecting fluoresced light. We present species-specific emission patterns among closely related species, indicating that biofluorescence potentially functions in intraspecific communication and evidence that fluorescence can be used for camouflage. This research provides insight into the distribution, evolution, and phenotypic variability of biofluorescence in marine lineages and examines the role this variation may play.

Effect of the color of the intraocular lens on optical and visual quality.

Purpose:To analyze the optical quality of intraocular lenses (IOL) with an orange (PC440Y) and a yellow (SN60AT) filter, and correlate these results with the visual quality of patients with these implants.Setting:Fisabio Oftalmología Médica, Valencia, Spain.Design:Randomized prospective study.Materials and Methods:The IOL optical quality was determined using the modulation transfer function (MTF) and the spectral transmission. The visual quality of 87 eyes with cataract (51 with orange filter and 36 with yellow filter) was determined by best corrected visual acuity (BCVA) and contrast sensitivity function (CSF) under photopic and mesopic conditions. To analyze the results, we use a Student's t-test.Results:Orange lens filtered more of the blue spectrum (cut-off wavelength of 370 nm) than the yellow lens (390 nm). The MTF of the yellow lens was better than the orange lens (average modulation of 0.676 for natural and 0.672 for orange). The patients’ BCVA was 0.02 + 0.10 logMAR for both lenses. The CSF obtained with the yellow lens was slightly better, although without statistically significant differences (P > 0.05).Conclusions:Both lenses are of good optical quality. The patients’ visual quality was similar with both lenses, and optical quality was also similar. The color of the lens does not affect the visual quality of the patient.

Oxidative stress and histological changes in a model of retinal phototoxicity in rabbits.

Photochemical damage occurs after an exposure to high energy radiation within the visible spectrum of light, causing morphological changes in the retina and the formation of superoxide anion. In this study we created a model of phototoxicity in rabbits. Animals were exposed to a light source for 120 minutes and were sacrificed immediately or one week after exposure. Outer nuclear layer and neurosensory retina thickness measurements and photoreceptor counting were performed. Caspase-1 and caspase-3 were assessed by immunohistochemistry. Dihydroethidium was used to evaluate in situ generation of superoxide and thiobarbituric acid reactive substances were measured in retinal homogenates as indicators of lipid peroxidation. The total antioxidant capacity and oxidative ratio were also determined. Retinas from rabbits exposed to light showed higher levels of lipid peroxidation than the unexposed animals and a decrease in outer nuclear layer and neurosensory retina thickness. Our study demonstrates that light damage produces an increase in retinal oxidative stress immediately after light exposure that decreases one week after exposure. However, some morphological alterations appear days after light exposure including apoptotic phenomena. This model may be useful in the future to study the protective effect of antioxidant substances or new intraocular lenses with yellow filters.

Comparaison de la morbidité de 2 prélèvements des tendons de la patte d’oie pour la reconstruction de ligament croisé antérieur

To determine the prevalence of papillary changes of the upper palpebral conjunctiva and folliculosis of the lower palpebral conjunctiva in Chinese children with no history of contact lens wear.Ninety-nine subjects (aged 6–15 years old) who were interested in a myopia control study were screened for papillary changes and folliculosis of the palpebral conjunctiva. Photodocumentation was performed under white and blue light (after the application of fluorescein) with a yellow filter and the photographs were graded by a group of practitioners according to a pre-set grading scale. Analysis was performed with the subjects divided into groups according to gender and age.More than 48% of the subjects had clinically significant (≥Grade 3) papillary changes in the upper palpebral conjunctiva. The prevalence of significant folliculosis in the lower lid was about 33%. The prevalence of significant papillary changes and folliculosis were similar between genders. No differences were observed between younger (age ≤ 10 years old) and older (age > 10 years old) in papillary changes but younger subjects showed a higher prevalence of folliculosis.The prevalences of clinically significant papillary changes and folliculosis of unknown aetiology are high in Chinese children.

The price for reduced light toxicity: Do endoilluminator spectral filters decrease color contrast during Brilliant Blue G–assisted chromovitrectomy?

BackgroundVitreoretinal surgeons have been slow to adopt the use of spectral filters for endoillumination to reduce retinal light toxicity. This study shows that spectral filters can be used without a loss in color contrast during brilliant blue G chromovitrectomy.MethodsTo evaluate the influence of intra operative spectral light filters on perceivable contrast during Brilliant Blue G chromovitrectomy, a prospective, observational clinical study was carried out on 59 consecutive Brilliant Blue G chromovitrectomy interventions in 59 patients admitted for macular holes, macular pucker or vitreomacular traction syndromes. Subsequent to peeling of the internal limiting membrane, six different illumination modes were enabled consecutively: mercury vapor, mercury vapor/xenon, and xenon followed by xenon combined with an amber, green or yellow spectral filter. Main outcome measure was the chromaticity spread between stained internal limiting membrane and unstained retina as a measure for the color contrast perceived by the human eye.ResultsMean chromaticity scores were similar for all light sources: mercury vapor 7.97, mercury vapor/xenon 7.96 (p = 0.96), and xenon 7.41 (p = 0.55). Compared to xenon, the additional use of endoillumination spectral filters did not change contrast recognizability: Chromaticity scores were 9.38 for the amber filter (p = 0.13), 6.63 for the green and 7.02 for the yellow filter (p = 0.37 and 0.64, respectively). When comparing the different filters head-to-head, the amber filter was superior to the green filter (p = 0.03), while the yellow was intermediate and not significantly different from either the amber (p = 0.08) or the green filter (p = 0.51).ConclusionsColor contrast perceptibility during Brilliant Blue G assisted chromovitrectomy is similar with mercury vapor, mercury vapor/xenon or xenon light sources. Spectral filters do not decrease color contrast recognizability. Head-to-head comparison shows a significant advantage for the amber over the green filter with respect to contrast generation, the yellow filter is intermediate. As spectral filters are known to greatly reduce retinal light toxicity, we suggest donor eye studies to validate whether the amber filter should be generally recommended for Brilliant Blue G chromovitrectomy.

Computer Simulation for Gradual Yellowing of Aged Lens and Its Application for Test Devices

This paper proposes a simulation algorithm to assess the gradual yellowing vision of the elderly, which refers to the predominance of yellowness in their vision due to aging of the ocular optic media. This algorithm employed the spectral transmittance property of a yellow filter to represent the color appearance perceived by elderly people with yellow vision, and modeled the changes in the color space through a spectrum change in light using the yellow filter effect. The spectral reflectivity data of 1269 Munsell matte color chips were used as reference data. Under the standard conditions of a D65 illuminant and a $10^{\circ}$ observer of 1964 CIE, the spectrum of the 1269 Munsell colors were processed through the yellow filter effect to simulate yellow vision. Various degrees of yellow vision were modeled according to the transmittance percentage of the yellow filter. The color differences before and after the yellow filter effect were calculated using the DE2000 formula, and the color pairs were selected based on the color difference function. These color pairs are distinguishable through normal vision, but the color difference diminishes as the degree of yellow vision increases. Assuming 80% of yellow vision effect, 17 color pairs out of $(1269{\times}1268)/2$ pairs were selected, and for the 90% of yellow vision effect, only 3 color pairs were selected. The result of this study can be utilized for the diagnosis system of gradual yellow vision, making various types of test charts with selected color pairs.

Does a yellow filter improve visual object categorization in normal aging?

ABSTRACTPrevious studies have shown that a yellow filter (CPF450) can increase contrast, motion sensitivity, vergence, and accommodation. We investigated whether a yellow filter can reduce age-related visual deficits. We tested two groups of 60 observers (mean age 24 vs. 72) in an object categorization task. Grayscale photographs of natural objects and artifacts were displayed either centrally or peripherally (21°) at low (8%) or medium (30%) contrast. There were three filter conditions (no filter, placebo filter, and yellow filter). Both groups of observers performed similarly on central and medium-contrast pictures. The deleterious effects of reduced contrast and eccentricity were stronger in elderly individuals. Moreover, the yellow filter globally improved the speed of categorization for the elderly participants. The decrease in response time in the yellow filter condition was larger when the stimuli were displayed peripherally in both groups. A yellow filter should be considered as a potential means for visual improvement in normal aging.

A comparison of two-coloured filter systems for treating visual reading difficulties

Purpose: Visual disturbances that make it difficult to read text are often termed “visual stress”. Coloured filters in spectacles may help some children overcome reading problems that are often caused by visual stress. It has been suggested that for optimal effect each child requires an individually prescribed colour for each eye, as determined in systems such as the “Harris Foundation” coloured filters. Alternatively, it has been argued that only blue or yellow filters, as used in the “Dyslexia Research Trust” (DRT) filter system, are necessary to affect the underlying physiology. Method: A randomised, double blind trial with 73 delayed readers, was undertaken to compare changes in reading and spelling as well as irregular and non-word reading skills after 3 months of wearing either the Harris or the DRT filters. Results: Reading improved significantly after wearing either type of filter (t = −8.4, p < 0.01), with 40% of the children improving their reading age by 6 months or more during the 3 month trial. However, spelling ability (t = 2.1, p = 0.05) and non-word reading (f = 4.7, p < 0.05) improved significantly more with the DRT than with the Harris filters. Conclusion: Education and rehabilitation professionals should therefore, consider coloured filters as an effective intervention for delayed readers experiencing visual stress.Implications for RehabilitationAny disability that impacts on a child’s capacity to read has serious implications for academic development as well as the ability to participate independently in activities of daily living.One reading disability, generally termed “visual stress”, is related to visual disturbances that make it difficult to read text.This research demonstrates the beneficial use of coloured filters for promoting visual reading capacity for children with visual stress.Professionals who are involved in the needs of children with reading delay, may like to consider the benefits that coloured filters can afford children with visual reading problems.

A Yellow Filter Improves Response Times to Low-Contrast Targets and Traffic Hazards

Anecdotal evidence suggests that some sunglass users prefer yellow tints for outdoor activities, such as driving, and research has suggested that such tints improve the apparent contrast and brightness of real-world objects. The aim of this study was to establish whether yellow filters resulted in objective improvements in performance for visual tasks relevant to driving. Response times of nine young (age [mean ± SD], 31.4 ± 6.7 years) and nine older (age, [mean ± SD], 74.6 ± 4.8) adults were measured using video presentations of traffic hazards (driving hazard perception task) and a simple low-contrast grating appeared at random peripheral locations on a computer screen. Response times were compared when participants wore a yellow filter (with and without a linear polarizer) versus a neutral density filter (with and without a linear polarizer). All lens combinations were matched to have similar luminance transmittances (~27%). In the driving hazard perception task, the young but not the older participants responded significantly more rapidly to hazards when wearing a yellow filter than with a luminance-matched neutral density filter (mean difference, 450 milliseconds). In the low-contrast grating task, younger participants also responded more quickly for the yellow filter condition but only when combined with a polarizer. Although response times increased with increasing stimulus eccentricity for the low-contrast grating task, for the younger participants, this slowing of response times with increased eccentricity was reduced in the presence of a yellow filter, indicating that perception of more peripheral objects may be improved by this filter combination. Yellow filters improve response times for younger adults for visual tasks relevant to driving.

Glare Disability, Photostress Recovery, and Chromatic Contrast: Relation to Macular Pigment and Serum Lutein and Zeaxanthin

A large body of research has linked macular lutein and zeaxanthin to reduced risk of degenerative eye disease. The earliest published hypothesis for the role of the pigments was not based on chronic protection but immediate function. Recent data on macular pigment (MP) have shown that screening the foveal cones from short-wave light does, in fact, result in improvements in photostress recovery (PR), glare disability (GD), and chromatic contrast (CC). This study examined those relations on a larger sample. A total of 150 young healthy subjects were assessed. Plasma samples were obtained from 100 subjects for HPLC quantification of serum xanthophylls. MP density was measured using customized heterochromatic flicker photometery. GD, PR, and CC were measured in Maxwellian view using a broadband xenon light source. GD was measured by increasing the intensity of an annulus until it veiled a central target. PR was measured as the time necessary to regain sight of a central target after a 5-second exposure to an intense bleaching light. CC was measured as the amount of light necessary in a 460-nm background to lose sight of a central target. MP density was significantly related to serum lutein and zeaxanthin combined (r = 0.31, P = 0.002), GD (r = 0.24, P = 0.0015), PR (r = -0.18, P = 0.01), and CC (r = 0.46, P = 0.00005). These results confirm earlier reports of a significant relation between variation in macular pigment optical density and immediate effects on visual function. As with many species, intraocular yellow filters in humans appear to improve many aspects of the visual stimulus. (ClinicalTrials.gov number, NCT00909090.).