Non-image-forming Research Articles

Including Dynamic Viewing Behavior in Determining Vertical Eye-Level Light: Does it Matter for Office Design?

ABSTRACT When considering non-image-forming (NIF) light effects on people, knowing the light vertically at eye-level is necessary. However, people are dynamic in their behavior and constantly change their posture and viewing direction. This means that light measured vertically toward a constant direction might differ from the actual light that reaches people’s eyes. If the difference is large, occupant behavior might need to be included in lighting design measurements and simulations predicting the potential of NIF light effects. This paper presents an experiment on the difference between the actual dynamic eye-level light of office workers while seated at a desk (dynamic condition) and light measured statically toward a computer screen (static condition). Eye-level light conditions in relation to NIF effects were quantified using the melanopic Equivalent Daylight Illuminance (mEDI) and the relative alerting response (r D ). Measured dynamic mEDI was 4% to 10% larger than the static one. Analysis of r D was not possible due to saturation of the response. The dominant face orientation was toward the computer screen, with a deviation in the horizontal and vertical direction within 15 degrees from the center. The results show that measuring and simulating personal light conditions of office workers statically toward a computer screen might be a small underestimation of actual eye-level light, but the relevance of this underestimation in lighting design practice is not evident.

Biophilic analogous patterns for light-responsive architecture during polar night: Examining the photobiological effects of electrical lighting on surface colour configuration

This paper investigates occupants' photobiological responses of biophilic analogous patterns such as electrical lighting and surface colour configuration during dark periods in northern architecture. Biophilic design establishes that the integration of nature-inspired architectural strategies could positively impact occupants’ photobiological responses to enhance well-being in locations with limited daylight access. Photobiological responses are indicated on image-forming (IF) and non-image forming (NIF) effects. IF relates to visual outcomes, reflected on vision and visual tasks, and measured in photopic units. NIF relates to non-visual outcomes such as the biological process of circadian clock stimulation and measured in melanopic units. Limited research addresses the impact of electrical lighting combined with surface colour (SC) configurations to optimize minimum lighting requirements at photopic and melanopic levels in an architectural setting. This research therefore examines eight surface colour configurations tested under three different luminaire positions set at warm, warm-white, and white correlated colour temperature (CCT). The variables generated 72 scenarios, which were captured through high dynamic range images (HDRi), analyzed, and post-processed to display false colour maps and values of illuminance, melanopic-Equivalent Daylight Illuminance (melanopic-EDI) and spatial colour temperature. Results demonstrate the spatial diversification generated by electrical lighting to different visual tasks and circadian stimulation over a day. The study also proved that several coloured surfaces and luminaire settings can generate similar photopic and melanopic lighting conditions despite their perceived spatial colour temperature. This research highlights the photobiological adjustment of biophilic coloured lighting ambiances provided by electrical systems in northern latitudes compromised by extreme photoperiod.

Evening prolonged relatively low melanopic equivalent daylight illuminance light exposure increases arousal before and during sleep without altering sleep structure

SummaryLight can influence many psychophysiological functions beyond vision, including alertness, circadian rhythm, and sleep, namely the non‐image forming (NIF) effects of light. Melanopic equivalent daylight illuminance (mel‐EDI) is currently recommended as the predictor of the NIF effects of light. Although light dose is also critical for entraining and regulating circadian cycle, it is still unknown whether relatively low mel‐EDI light exposure for prolonged duration in the evening would affect pre‐sleep arousal and subsequent sleep. In all, 18 healthy college students (10 females, mean [standard deviation] age 21.67 [2.03] years) underwent 2 experimental nights with a 1 week interval in a simulated bedroom environment. During experimental nights, participants were either exposed to high or low mel‐EDI light (73 versus 38 lx mel‐EDI, 90 versus 87 photopic lx at eye level, 150 photopic lx at table level) for 3.5 h before regular bedtime, and their sleep was monitored by polysomnography. Subjective sleepiness, mood, and resting‐state electroencephalography during light exposure were also investigated. Results showed no significant differences in sleep structure and sleep quality between the two light conditions, whereas 3.5 h of exposure to high versus low mel‐EDI light induced marginally higher physiological arousal in terms of a lower delta but higher beta power density before sleep, as well as a lower delta power density during sleep. Moreover, participants felt happier before sleep under exposure to high versus low mel‐EDI light. These findings together with the current literature suggest that evening prolonged relatively low mel‐EDI light exposure may mildly increase arousal before and during sleep but affected sleep structure less.

Seasonal Variation in the Responsiveness of the Melanopsin System to Evening Light: Why We Should Report Season When Collecting Data in Human Sleep and Circadian Studies.

It is well known that variations in light exposure during the day affect light sensitivity in the evening. More daylight reduces sensitivity, and less daylight increases it. On average days, we spend less time outdoors in winter and receive far less light than in summer. Therefore, it could be relevant when collecting research data on the non-image forming (NIF) effects of light on circadian rhythms and sleep. In fact, studies conducted only in winter may result in more pronounced NIF effects than in summer. Here, we systematically collected information on the extent to which studies on the NIF effects of evening light include information on season and/or light history. We found that more studies were conducted in winter than in summer and that reporting when a study was conducted or measuring individual light history is not currently a standard in sleep and circadian research. In addition, we sought to evaluate seasonal variations in a previously published dataset of 72 participants investigating circadian and sleep effects of evening light exposure in a laboratory protocol where daytime light history was not controlled. In this study, we selectively modulated melanopic irradiance at four different light levels (<90 lx). Here, we aimed to retrospectively evaluate seasonal variations in the responsiveness of the melanopsin system by combining all data sets in an exploratory manner. Our analyses suggest that light sensitivity is indeed reduced in summer compared to winter. Thus, to increase the reproducibility of NIF effects on sleep and circadian measures, we recommend an assessment of the light history and encourage standardization of reporting guidelines on the seasonal distribution of measurements.

Melanopsin's Newly Identified Functions Related to Behavioral Light Adaptation

The ability of behavior and physiology to adjust to variations in ambient light brightness is essential to survival. These adaptations include the circadian clock's alignment of physiology and behavior to the day-night cycle and the modulation of neuroendocrine activity by light. These non-image-forming (NIF) responses are dependent on ocular light receipt but can work independently of rod and cone photoreceptors, indicating the involvement of novel photoreceptors in the eye. A fascinating entrance point to understanding how mammals adjust to the light environment has been made possible by the discovery of melanopsin in intrinsically photosensitive retinal ganglion cells (ipRGCs) and genetic evidence for its significant role in major NIF responses. Here, we examine the most recent developments in our knowledge of the ipRGCs and melanopsin's newly emerging roles. These discoveries now open up new perspectives on how ambient light affects alertness, sleep, dependent physiologies, potential pharmacological intervention, and lifestyle changes to enhance quality of life.

Enhancing learning Environments: Exploring optimal classroom design connected to Double-Loaded corridors across the U.S. Climate zones

Buildings’ envelope design decisions are usually determined by the architect or designer from the early stages of design. These decisions have a major impact on the comfort conditions and energy performance of buildings. Balancing daylighting levels in school buildings with the energy use is essential due to the physiological, psychological, and behavioral effects of daylight on human body, known as the non-image forming (NIF) effects of light, as well as its impact on the energy use. This study uses multi-objective optimization (MOO) to find the optimal classroom design that has the best overall performance in terms of daylighting levels at the horizontal desk-plane for image-forming (IF) or visual benefits, daylighting at the vertical eye-level for NIF benefits, and the total energy use of classrooms. The study optimizes two classrooms connected to double-loaded corridor from the Department of Energy (DOE) primary school reference building. The optimization parameters include the classroom geometry (width, depth, and height), the window dimensions (width and head height), and the orientation. The impact of the location factor is explored by optimizing the same model in the mixed-humid, hot-humid, hot-dry, and cold climate zones of the U.S. The results indicate that the 3:2 width-to-depth plan shape in most optimal solutions performs better than the 5:4 width-to-depth plan of the reference model. Accordingly, wider windows and higher head height in the optimal design were able to allow more daylighting to the depth of the oppositely oriented classrooms while reducing the energy use. The results show that optimal classrooms’ design connected to double-loaded corridors, including window dimensions, orientation, and window to wall ratio (WWR) vary by the climate zone or location.

BDE-47 Causes Depression-like Effects in Zebrafish Larvae via a Non-Image-Forming Visual Mechanism.

Depression is a high-incidence mood disorder that is frequently accompanied by sleep disturbances, which can be triggered by the non-image-forming (NIF) visual system. Therefore, we hypothesize that polybrominated diphenyl ethers are known to induce visual impairment that could promote depression by disrupting the NIF visual pathway. In this study, zebrafish larvae were exposed to BDE-47 at environmentally relevant concentrations (2.5 and 25 μg/L). BDE-47 caused melanopsin genes that dominate the NIF visual system that fell at night (p < 0.05) but rose in the morning (p < 0.05). Such bidirectional difference transmitted to clock genes and neuropeptides in the suprachiasmatic nucleus and impacted the adjacent serotonin system. However, indicative factors of depression, including serta, htr1aa, and aanat2, were unidirectionally increased 1.3- to 1.6-fold (p < 0.05). They were consistent with the increase in nighttime thigmotaxis (p < 0.05) and circadian hypoactivity (p < 0.05). The results of melanopsin antagonism also indicated that these consequences were possibly due to the combination of direct photoentrainment by melanopsin and circadian disruption originating from melanopsin. Collectively, our findings revealed that BDE-47 exposure disrupted the NIF visual pathway and resulted in depression-like effects, which may further exert profound health effects like mood disorders.

Light as a Modulator of Non-Image-Forming Brain Functions-Positive and Negative Impacts of Increasing Light Availability.

Light use is rising steeply, mainly because of the advent of light-emitting diode (LED) devices. LEDs are frequently blue-enriched light sources and may have different impacts on the non-image forming (NIF) system, which is maximally sensitive to blue-wavelength light. Most importantly, the timing of LED device use is widespread, leading to novel light exposure patterns on the NIF system. The goal of this narrative review is to discuss the multiple aspects that we think should be accounted for when attempting to predict how this situation will affect the NIF impact of light on brain functions. We first cover both the image-forming and NIF pathways of the brain. We then detail our current understanding of the impact of light on human cognition, sleep, alertness, and mood. Finally, we discuss questions concerning the adoption of LED lighting and screens, which offer new opportunities to improve well-being, but also raise concerns about increasing light exposure, which may be detrimental to health, particularly in the evening.

Müller glial cell photosensitivity: A novel function bringing higher complexity to vertebrate retinal physiology

The retina of vertebrates is responsible for detecting and capturing ambient light for image and non-image forming (NIF) functions through diverse projections to the brain which regulate visual processing, pupillary light responses, photic synchronization of circadian rhythms and suppression of pineal melatonin, among others. For this, vertebrates have retained through evolution at least two sets of photoreceptors specialized primarily in such visual and NIF tasks: visual photoreceptors cones and rods responsible for day/night vision, and intrinsically photosensitive retinal ganglion cells (ipRGC) together with horizontal cells in some vertebrates, expressing melanopsin (Opn4). Interestingly, Opn4 as well as encephalopsin (Opn3) and neuropsin (Opn5), responding to blue and UV light, respectively, are expressed in the inner retina and command light detection in the blue range of the visible spectra; they are responsible for a number of NIF functions still lacking characterization. Though most retinal photoreceptors are derived from ciliary or neuronal progenitor cells, in recent years Müller glial cells (MCs), the most abundant retinal glial cell type, have been shown to express different blue opsins (Opn3 and Opn5) and the photoisomerase retinal G protein-coupled receptor (RGR), and to respond directly to light. MCs display different essential functions to maintain the homeostasis and cell survival of the whole retina, contributing to glutamate metabolism and chromophore recycling. The novel photoreceptive capacity of MCs, mainly in the blue region, offers several highly intriguing possibilities that increase the complexity levels for light detection in the retina and its light-activated circuits, calling for further investigation. The goal of the present review is to discuss the state of the art of research on the principal macroglial cells in the retina, focusing mainly on the novel photic responses driven by MCs, the biochemical mechanisms triggered after light stimulation and their putative functions and implications.

Diurnal effects of dynamic lighting on alertness, cognition, and mood of mentally fatigued individuals in a daylight deprived environment

This study investigated the non-image forming (NIF) effects of dynamic light on alertness, cognitive performance and mood on mental fatigue, as well as moderation of task difficulty in lighting perception. Sixteen participants completed a psychomotor vigilance test (PVT) and two complex cognitive tasks (multi-attribute task battery-II (MATB-II) and n-back) with low, medium and high difficulty levels under dynamic (4000 to 12 000 K, melanopic equivalent daylight illuminance (EDI) = 224 lx to 420 lx) and static (4000 K, melanopic EDI = 224 lx) lighting with illuminance set at 500 lx on the desk. Psychological, behavioural, biochemical and electrophysiological responses to light were assessed. The results showed that exposure to dynamic light had significant benefits on subjective sleepiness, positive mood and task performance, which may be moderated by task difficulty. The intervention effect of dynamic light on fatigue was also found during an electrophysiological activity due to increase in the amount of attentional resources allocated to the tasks by dynamic light, but was not observed in biochemical measures.

Simulations of non-image-forming effects of light in building design: A literature review

Light affects many aspects of human physiology, through the non-image-forming (NIF) pathway. To account for this pathway, lighting design simulation tools need to combine several luminous and temporal factors to predict how architectural and lighting design decisions affect eye-level light exposure. Based on a systematic literature review, containing 55 journal and conference papers, the state-of-the-art towards implementing lighting beyond vision in computer simulation workflows for building design is presented. The review shows that, while interest in simulating the NIF effects of light on people is increasing, there is not a common method to perform these simulations. Gaps were identified in the currently available simulation workflows in relation to metrics, software and approaches for predicting NIF effects of light in the context of the building design.

Characterisation of pupillary responses to alternating blue and orange light exposures in a fMRI protocol

AbstractBackgroundThe non‐image forming (NIF) functions of light are diverse and include stimulation of cognition and alertness, sleep regulation and pupil diameter modulation. Previous work indicated that exposure to blue‐enriched light as well as pupil size variations are associated with higher locus coeruleus (LC) activity. Given the central role of LC structure and function in the earliest stages of Alzheimer’s disease neuropathology, light exposure may constitute a promising stimulation technique to delay disease progression. Prior to addressing light impact on the LC, here, we aimed at characterising the pupil responses to light during fMRI protocol, to determine its quality in assessing NIF effects of light.MethodPupil diameter was continuously recorded in 11 healthy subjects (20‐30yr, 7 women) with an infrared eyetracker device while they were administered a 15‐min auditory oddball task in a 7T MRI scanner. Participants were concomitantly exposed to pseudo‐randomly alternating 30s blocks of blue‐enriched (4,000K; 200µW/cm2) and orange (589nm; 6x1013photons/cm2/s) lights. Statistics consisted in generalized linear mixed models seeking effects of light condition on pupil response, with subjects as random intercept and controlling for age, sex and BMI.ResultBlue light condition was associated with a significantly smaller pupil diameter as compared to the orange condition, (main effect of light condition: F(2,270)=571.22;p&lt;.0001; Fig1). Moreover, the impact of the light condition on pupil size did not significantly change over the 15min‐protocol (light condition x block repetition interaction: F(12,240)=1.21 ; p=.28), suggesting that time‐in‐protocol and prior light blocks did not influence pupil constriction.ConclusionWe report preliminary results confirming that blue‐enriched light triggers a stronger pupil response than longer wavelength light and showing that the protocol induces a stable response in time even when using short alternating light exposures. These findings support the validity of the protocol to assess NIF responses to light in fMRI in healthy participants, including over the LC. Being able to stimulate the LC holds important implications for possibly delaying Alzheimer’s disease progression. We now aim to include more participants, including older individuals, and to extend to other cognitive tasks to assess the generalization of the present findings to other cognitive domains and age‐ranges.

Non-image forming potential in urban settings – An approach considering orientation-dependent spectral properties of daylight

This paper introduces a novel approach to integrate orientation-dependent spectral properties of daylight in urban planning. These spectral characteristics of light at façades are represented in spectral daylight potential diagrams (SDPDs). The applicability of SDPDs is subsequently discussed in the context of non-image forming (NIF) effects, comparing the NIF effectiveness of skylight at façades—represented in the melanopic daylight (D65) efficacy ratio —based on SDPDs to the generally assumed CIE standard illuminant D65 and the horizontal correlated colour temperature (CCT) widely used in existing software. This analysis comprises the impact of (i) prevailing sky conditions and (ii) obstruction levels on the spectral characteristics of skylight on different façade orientations.Our core findings suggest that not considering the directionality of the colour information of skylight from clear sky conditions might lead to underestimation (D65) or overestimation (horizontal CCT) of the NIF effectiveness of skylight offered at façades. When designing for NIF responses, the first potentially leading to increased energy consumption, the latter to a lower NIF response as designed for. These findings not only advance our scientific knowledge of the spectral properties of daylight but also provide a simplified methodological framework for assessing the NIF effectiveness of daylight in urban settings.

A new tool and workflow for the simulation of the non-image forming effects of light

Other than supporting vision, light plays an important role in regulating human circadian rhythms through its non-image-forming (NIF) effects. Simulating potential NIF stimulation from daylight indoors, however, is a challenging task, requiring the continuous evaluation of luminous exposures at the eye, which are affected by changing sky's spectral power distributions at a location, time of day and year, and estimation of the sky patches’ contributions at a viewing position, which dynamically vary through a space. Existing multi-channel NIF simulations tools use measured or pre-computed spectral sky data. Yet, these are difficult to obtain with flexible spatio-temporal resolution. To address this challenge, and dynamically estimate a range of NIF metrics, we developed a tool and workflow based on 17 original Python-scripted Grasshopper components. This paper illustrates the design and development of the tool and workflow, also presenting an example of practical application to evaluate the yearly variations of potential NIF stimulation from an interior position or under an unobstructed sky. This is the first step to propose more robust building design and modelling concepts, beyond conventional visual comfort issues, and to adequately balance lighting energy use with occupants’ comprehensive needs, while connecting daylighting and electric lighting systems and controls within integrated solutions.

Reconstruction of Daylight Spectral Power Distribution Based on Correlated Color Temperature: A Comparative Study between the CIE Approach and Localized Procedures in Assessing Non-image Forming Effects

ABSTRACT Spectrally and spatially resolved information on daylight is critically important when planning for non-image forming (NIF) responses. Nevertheless, the availability of such data is scarce given the high initial costs and complex on-site maintenance of high-end spectral measurement devices. The CIE (Commission Internationale de l’Éclairage) reconstruction procedure allows for the derivation of the daylight spectral power distribution (SPD) from the chromaticity coordinates or the correlated color temperature (). However, several studies have suggested that both the daylight locus and the reconstruction procedure are erroneous, and specifically SPDs with a higher cannot be reproduced accurately. This paper studies the reconstruction accuracy of the SPD of daylight, and contextualizes the findings in relation to NIF effects. The analysis comprises a comparative study to determine the accuracy of the CIE procedure compared to two localized reconstruction procedures, and a sensitivity study to examine the impact of accuracy on the assessment of NIF responses, as represented by all five retinal photoreceptors and expressed in the α-opic efficacy of luminous radiation. The results indicated that a localized procedure, adjusting both the daylight locus and the PCA components of daylight, outperformed the CIE reconstruction method. However, improvement in the reconstruction accuracy had no effect on NIF assessment. The RSMPE for α-opic quantities did not exceed 4% for any procedure. In practical terms, this implies that cost-effective sensors and the representation of spectral properties in sky models with a single value – the correlated color temperature – can be used for NIF purposes. These findings bridge theory and practice by opening up new insights into the understanding of simplified methods used to determine NIF effects of daylight.

Review of spectral lighting simulation tools for non-image- forming effects of light

Light via our eyes influences visual performance, visual comfort and visual experience, but also affects several health related, non-image-forming (NIF) responses. New metrics have been developed to quantify the NIF effects of light. In order to incorporate these in lighting design practice, simulation tools are required that are able to process information about the spectral distribution of light sources and materials. However, most of the tools currently used for daylight and electric light simulations simplify the spectrum into RGB (Red, Green, Blue) colour values. This paper presents an overview of the currently used programs for simulating the NIF effects of light in building design and discusses the possibility of using existing spectral rendering software as an alternative. A review of literature shows that mostly Radiance or Radiance-based programs have been used so far, but new user-friendly tools could employ existing spectral rendering tools. As the NIF effects of light gain greater importance in lighting design, new simulation workflows are needed. This paper aims to support the development of future workflows by presenting the current state-of-the-art.

Effects of illuminance and correlated color temperature of indoor light on emotion perception

The acute non-image forming (NIF) effects of daytime light on momentary mood had been-although not always-established in the current literature. It still remains largely unknown whether short-time light exposure would modulate emotion perception in healthy adults. The current study (N = 48) was conducted to explore the effects of illuminance (100 lx vs. 1000 lx at eye level) and correlated color temperature (CCT, 2700 K vs. 6500 K) on explicit and implicit emotion perception that was assessed with emotional face judgment task and emotional oddball task respectively. Results showed that lower CCT significantly decreased negative response bias in the face judgment task, with labeling ambiguous faces less fearful under 2700 K vs. 6500 K condition. Moreover, participants responded slightly faster for emotional pictures under 6500 K vs. 2700 K condition, but no significant effect of illuminance or CCT on negativity bias was revealed in the emotional oddball task. These findings highlighted the differential role of illuminance and CCT in regulating instant emotion perception and suggested a task-dependent moderation of light spectrum on negativity bias.

Brain functional MRI responses to blue light stimulation in Leber’s hereditary optic neuropathy

Melanopsin retinal ganglion cells (mRGCs) are intrinsically photosensitive photoreceptors contributing both to image and non-image-forming (NIF) functions of the eye. They convey light signal to the brain to modulate circadian entrainment, sleep, alertness, cognition, brightness perception and coarse vision. Given that rods and cones also contribute to all these impacts of light, isolating mRGC visual and NIF roles in humans is challenging so that mRGC functions remains to be fully characterized. Here, we evaluated light-driven visual and cognitive brain responses in Leber’s Hereditary Optic Neuropathy (LHON), an inherited optic neuropathy that is characterized by a selective relative sparing of the melanopsin-expressing retinal ganglion cells (mRGCs). Twelve patients and twelve matched healthy controls (HC) were enrolled in a functional brain magnetic resonance imaging (fMRI) protocol including visual and visual-cognitive paradigms under blue (480 nm) and red (620 nm) light exposures. Primary visual cortex activation was detected in LHON patients; in particular higher occipital activation was found in response to sustained blue vs. red stimulation in LHON vs. HC. Similarly, brain responses to the executive task were larger under blue vs. red light in LHON over lateral prefrontal cortex. These findings are in line with the relative mRGC sparing demonstrated in LHON and support the mRGC contribution to both non-visual and visual brain functions, with potential implication for visual rehabilitation in hereditary optic neuropathy patients.

Age-related neuroendocrine and alerting responses to light.

Aging is associated with sleep and circadian alterations, which can negatively affect quality of life and longevity. Importantly, the age-related reduction in light sensitivity, particularly in the short-wavelength range, may underlie sleep and circadian alterations in older people. While evidence suggests that non-image-forming (NIF) light responses may diminish in older individuals, most laboratory studies have low sample sizes, use non-ecological light settings (e.g.,monochromatic light), and typically focus on melatonin suppression by light. Here, we investigated whether NIF light effects on endogenousmelatonin levels and sleep frontal slow-wave activity (primary outcomes), and subjective sleepiness and sustained attention (secondary outcomes) attenuate with aging. We conducted a stringently controlled within-subject study with 3 laboratory protocols separated by ~ 1 week in 31 young (18-30 years; 15 women) and 16 older individuals (55-80 years; eight women). Each protocol included 2 h of evening exposure to commercially available blue-enriched polychromatic light (6500 K) or non-blue-enriched light (3000 K or 2500 K) at low levels (~ 40 lx, habitual in evening indoor settings). Aging significantly affected the influence of light on endogenousmelatonin levels, subjective sleepiness, sustained attention, and frontal slow-wave activity (interaction: P < 0.001, P = 0.004, P = 0.007, P = 0.001, respectively). In youngindividuals, light exposure at 6500 K significantly attenuated the increase in endogenousmelatonin levels, improved subjective sleepiness and sustained attention performance, and decreased frontalslow-wave activity in the beginning of sleep. Conversely, older individuals did not exhibit signficantdifferential light sensitivity effects. Our findings provide evidence for an association of aging and reduced light sensitivity, with ramifications to sleep, cognition, and circadian health in older people.

Cell-Subtype-Specific Remodeling of Intrinsically Photosensitive Retinal Ganglion Cells in Streptozotocin-Induced Diabetic Mice

Recent evidence suggests that melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs), a neuronal class regulating non-image forming (NIF) vision and generally thought to be injury-resistant, are dysfunctional in certain neurodegenerative diseases. Although disrupted NIF visual functions have been reported in patients and animals with diabetes, it remains controversial whether ipRGCs exhibit remodeling during diabetes and if so, whether such remodeling is variable among ipRGC subtypes. Here we demonstrate that survival, soma-dendritic profiles and melanopsin-based functional activity of M1 ipRGCs were unaltered in streptozotocin-induced 3-month diabetic mice. Such resistance remained at 6 months after streptozotocin administration. In contrast, M2/M3 ipRGCs underwent significant remodeling in diabetic mice, manifested by enlarged somata and increased dendritic branching complexity. Consistent with the unaltered melanopsin levels, the sensitivity of melanopsin-based activity was unchanged in surviving M2 cells, but their response gain displayed a compensatory enhancement. Meanwhile, the pupillary light reflex, a NIF visual function controlled by M2 cells, was found to be impaired in diabetic animals. The resistance of M1 cells might be attributed to the adjacency of their dendrites to capillaries, which makes them less disturbed by the impaired retinal blood supply at the early stage of diabetes.