Artificial Eye Research Articles

Mosaic-free compound eye camera based on multidirectional photodetectors and single-pixel imaging.

Compound-eye wide field-of-view (FOV) imaging generally faces the disadvantages of a complex system, low resolution, and complicated image mosaic. Single-pixel imaging has proven to very beneficial in building a high-resolution and simple wide-FOV camera, but its ability to overcome the problem of image mosaics still needs to be demonstrated. In this Letter, we propose a novel, to the best of our knowledge, kind of artificial compound eye based on multidirectional photodetectors (PDs) and demonstrate theoretically and experimentally that mosaics are unnecessary in multidirectional PD-based single-pixel imaging. In addition, we show experimentally that only nine multidirectional PDs are needed to obtain wide-angle images in a hemisphere to realize wide-FOV mosaic-free imaging. This work greatly simplifies the concept of compound-eye cameras and is very enlightening for detector design in wide-FOV single-pixel imaging, plausibly leading to the development of single-pixel endoscopic imaging.

Remarkable Predictions in Azerbaijani Science Fiction Literature

In the article, the topic of predictions, which is one of the factors that form the basis of science fiction works written in Azerbaijani literature, is covered in a wide and detailed manner, historical and scientific evaluation is given to them. Azerbaijani science fiction works are closely related to Western European science fiction literature and have reached certain achievements in this field. It is known that one of the main themes of science fiction works is the predictability factor. The article has analized the important predictions described in the works of “The Future City” written by Y.V. Chamanzaminli and “RT-1”, “Polar Lights in Mughan”, “ When Missouri Overflowed”, “Symphony of Life”, “The Spaceship” by Emin Mahmudov, “The Adventures of a Little Cyber” by Namig Abdullayev and the predictions that have been confirmed according to the period of writing are revealed and studied. In the work of “The Future City” Y.V. Chamanzaminli predicted an effective method of the distance examination and treatment through the Internet; possibility of artificial rain; a special device with a safety sensor installed in cars used in our days, which is the latest achievement of modern technology, electronic billboards and monitors displaying announcements, political and public information, city events, and weather information; medical innovations such as USI – medical examination with the help of ultraviolet rays, CT – computer tomography, laser crushing of kidney stones into small pieces and removing them by laser, transplantation of organs such as heart and liver, artificial eye and other new technologies. The predictions described in the work shows that the well-known Azerbaijani prose writer Y.V. Chamanzaminli gave deep information about the innovations in medical sciences, significantly anticipating the writing period in the first half of the last century. The results obtained on the basis of the analyzes carried out in the research are of both theoretical and practical importance.

Ocular Prosthesis: What you need to know and the current challenges in Nigeria

Ocular prosthesis (OP) is the replacement of natural eye by an artificial material following eye removal. OP is also called artificial eye; it gives no vision but improve the quality of life in an anophthalmic patient. OP is mainly used following ocular destructive surgery (evisceration, enucleation and exenteration.). Evisceration is the removal of intraocular content leaving scleral and optic nerve, while enucleation is the removal of the whole eye ball including the optic nerve. Exenteration is the removal of the whole eye including: optic nerve, eye adnexial and part of orbital bone. There are various challenges facing the usage of OP in Nigeria. There is a need to create awareness on the importance of ocular prosthesis, its use, types and production as well as the need to set up school of Ocularistry in Nigeria.

Nodular Episcleritis in a Boy with Pulmonary Tuberculosis

Introduction: Episcleritis is an acute inflammation of the vascular connective tissue between the conjunctiva and the sclera’s surface, which can be found unilateral and bilateral. Tuberculosis (TB) is one of the systemic infectious diseases that cause morbidity in developing countries and can affect the ocular area known as ocular tuberculosis There are still limited cases of ocular tuberculosis studies, specifically tubercular nodular episcleritis in adolescents. This case report aims to expose nodular episcleritis in pediatric tuberculosis patients in Indonesia. Case Presentation: A 16-year-old boy came to the Community Eye Health Hospital East Java with superior bilateral eye redness and pain with normal visual acuity. He underwent advanced anti-tubercular treatment for the last nine months. The best corrected visual acuity (BCVA) of both eyes was 6/6. Slit-lamp biomicroscopy (SLB) examination found the dilation of blood vessels located on the superior episclera accompanied by a firmly bordered, fixed, pink nodule, diameter ± 1.5 mm located at 12 o’clock in bilateral bulbar conjunctiva. Based on anamnesis and physical examination, the diagnosis of nodular episcleritis et causa pulmonary TB was established. Topical corticosteroids and artificial tears eyedrops were given in both eyes for five weeks, and continuing anti-tubercular treatment was performed. Conclusion: It is necessary to investigate the primary cause of episcleritis by eliminating underlying systemic diseases. Herein, we present a rare case of nodular episcleritis in an adolescent with pulmonary tuberculosis who responded very well to anti-tubercular treatment with topical corticosteroid and artificial tears eye drops.

Visible light-driven indium-gallium-zinc-oxide optoelectronic synaptic transistor with defect engineering for neuromorphic computing system and artificial intelligence

There has been considerable interest in the development of optoelectronic synaptic transistors with synaptic functions and neural computations. These neuromorphic devices exhibit high-efficiency energy consumption and fast operation by imitating biological neural computation methods. Here, a simple defect engineering method for oxide semiconductors is proposed so that indium‑gallium‑zinc-oxide (IGZO) optoelectronic synaptic transistors can have synaptic behavior even in the long-wavelength-visible-light region, in which it is difficult to stimulate the conventional oxide semiconductor. Two additional defective layers (the defective interface layer and light absorption layer) are controlled to generate defects that improve the synaptic function and visible-light absorption. The IGZO optoelectronic synaptic transistor with defect engineering shows the peak of photo-induced postsynaptic current (PSC) of 17.04 nA and maximum gain of 24.67 with 25 optical pulses and a 198% paired-pulse facilitation (PPF) index under red-light illumination at a 635-nm wavelength. Furthermore, learning and forgetting were mimicked by optical and electrical signals, as demonstrated in a “Pavlov's dog” experiment. These results demonstrate that IGZO optoelectronic synaptic transistors can be used in various optical applications driven by a wide range of visible light, such as artificial eyes or intelligent display products.

Humidity Sensor to Support Dry Eye Diagnosis Based on Polymeric PVDF Transfer Membrane

A system based on polyvinylidene fluoride (PVDF) polymeric transfer membrane was developed as an ocular humidity sensor to support the diagnosis of dry eye. An experimental arrangement was implemented where the devices utilized to observe the behavior of PVDF transfer membrane as a humidity sensor were installed, on the contour of an artificial eye model, held with a contact lens, formed by an elastic balloon that is exposed to triple distilled water and artificial tears, on the order of 0– <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$40~\mu \text{L}$ </tex-math></inline-formula> , with a resolution of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10~\mu \text{L}$ </tex-math></inline-formula> . Measures were taken simulating four constant intraocular pressures (IOPs), i.e., 10, 15, 20, and 25 mmHg. The pressure exerted on both elastic artificial eyes is done simultaneously through communicating vessels. Similarly, the IOP of the artificial eye was recorded using a Schiötz tonometer and an MPX2010 GP sensor, in the range of 10–25 mmHg. The response of the PVDF transfer membrane showed a proportional relationship between capacitance changes and humidity (lack of humidity or dryness) in the artificial eye model. Capacitance measurements were made at room temperature at 25 °C, using an HM818-Rohde and Schwarz bridge <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit {LCR}$ </tex-math></inline-formula> meter. Finally, capacitance response was converted to frequency with an astable oscillator to optimize signal processing and visualization. These polymeric PVDF transfer membranes sensors are a hydrophobic material, which prevents the storage of water molecules in the sensing material and allows liquid or artificial tears to flow freely. In summary, polymeric PVDF transfer membranes exhibit suitable properties as a dry eye humidity sensor at realistic IOPs.

Qualitative Study for the Design and Fabricate of Assistive Technologies for the Visually Impaired and Blind People to Improve the Quality of Life

From the distant past until now, various assistive devices and equipment have been made and marketed for the purpose of improving the life of blind people. Braille and the white cane can be noted as one of the most basic auxiliary equipment for the blind people. Over time and through the advancement of technology, a great change has taken place in the world of the blinds; and we can see everyday development of various tools which all of them are useful in improving the life of the blind people. Today, there are various helpful tools for the blind including Obstacle detection gadgets, Text reading tools, Money detection systems, Routing systems, Audio clock, Brain port, Braille tablet, Artificial eyes (bionic eyes), etc. In this article, we will have an overview of assistive devices made for the blinds. Examination of the produced medical equipment in this field will make it possible to provide more qualified assistive equipment for the blind.

Opto-Mechanical Eye Models, a Review on Human Vision Applications and Perspectives for Use in Industry

The purpose of this review is to aggregate technical information on existent optomechanical eye models (OME) described in the literature, for image quality assessment in different applications. Several physical eye models have been reviewed from peer-reviewed papers and patent applications. A typical eye model includes an artificial cornea, an intraocular lens or other lens to simulate the crystalline lens, an aperture as the pupil, and a posterior retinal surface, which may be connected to a light sensor. The interior of the eye model may be filled with a fluid to better emulate physiological conditions. The main focus of this review is the materials and physical characteristics used and the dimensional aspects of the main components including lenses, apertures, chambers, imaging sensors and filling medium. Various devices are described with their applications and technical details, which are systematically tabulated highlighting their main characteristics and applications. The models presented are detailed and discussed individually, and the features of different models are compared when applicable, highlighting strengths and limitations. In the end there is a brief discussion about the potential use of artificial eye models for industrial applications.

Chalcogenide Glass IR Artificial Compound Eyes Based on Femtosecond Laser Microfabrication

AbstractThe compact and lightweight infrared (IR) optics devices are highly demanded in booming applications. However, fabrication of IR optics devices with high efficiency is still technically challenging, especially artificial compound eyes (ACE) with low aberration imaging and large field of view. In this work, a method of femtosecond laser wet etching combining with the “two‐step” precision glass molding based on chalcogenide glass is proposed to fabricate glass IR ACE. The as‐prepared consists of 6000 ommatidia (diameter of 88 µm and the sag height of 11 µm) arranged in a hexagonal manner with perfect parabolic morphology and high uniformity. The chalcogenide glass IR ACE exhibits excellent optical performance both in IR active imaging and IR passive imaging with high transmittance (60–70%) ranging from 2.5 to 15 µm. The ommatidia have a high resolution up to 20.16 lp mm−1, and imaging with large field of view up to 60° and low aberration can be achieved. Furthermore, the proposed technology shows advantages to fabricate glass IR ACE with low cost and high efficiency, and glass IR ACE shows great potential in IR imaging, robot vision, IR 3D motion tracking, and so on.

Artificial Hyper Compound Eyes Enable Variable-Focus Imaging on both Curved and Flat Surfaces.

The artificial compound eye (ACE) with zoom imaging requires complex power sources. Meanwhile, its curved substrate makes it difficult for the ACE to realize the zoom imaging on flat surfaces. To realize a wide field of view and a zoom function on both curved and flat surfaces simultaneously, a novel ACE is proposed, which is a bionic design inspired by an ancient creature, trilobite. Compared with a dragonfly, photosensitive units of a trilobite's compound eye are composed of ommatidia with different focal lengths. By learning from this concept, an artificial hyper compound eye (AHCE) was fabricated. Its basic components are five microlenses with different curvatures, and they are capable of being treated as five ommatidia with different focal lengths. Five ommatidia form a photosensitive unit to realize a zoom function. AHCE is capable of variable-focus imaging on curved surfaces. With the information share function, we found that the AHCE not only images on curved surfaces but also has a zoom-imaging function on flat surfaces. The results confirm that the AHCE demonstrates an advanced imaging capability, a variable-focus imaging function on both curved and flat surfaces, which may open new opportunities in developing advanced micro-optical devices.

Dispersion-free highly accurate color recognition using excitonic 2D materials and machine learning

Dispersion is accepted as a fundamental step required for analyzing broadband light. The recognition of color by the human eye, its digital reproduction by a camera, or detailed analysis by a spectrometer all utilize dispersion; it is also an inherent component of color detection and machine vision. Here, we present a device (called artificial eye or, A-Eye) that accurately recognizes and reproduces tested colors, without any spectral dispersion. Instead, A-Eye uses N = 3–12 transmissive windows each with unique spectral features resulting from the broadband transmittance and excitonic peak-features of 2D transition metal dichalcogenides. Colored light passing through (and modified by) these windows and incident on a single photodetector generated different photocurrents, and these were used to create a reference database (training set) for 1337 “seen” and 0.55 million synthesized “unseen” colors. By “looking” at test colors modified by these windows, A-Eye can accurately recognize and reproduce “seen” colors with zero deviation from their original spectra and “unseen” colors with only ∼1 % median deviation, using the k-NN algorithm. A-Eye can continuously improve color estimation by adding any corrected guesses to its training database. A-Eye’s accurate color recognition dispels the notion that dispersion of colors is a prerequisite for color identification and paves the way for ultra-reliable color-recognition by machines with reduced engineering complexity.

A cross-over, randomised feasibility study of digitally printed versus hand-painted artificial eyes in adults: PERSONAL-EYE-S - a study protocol

Background/objectives: Around 11,500 artificial eyes are required yearly for new and existing patients. Artificial eyes have been manufactured and hand-painted at the National Artificial Eye Service (NAES) since 1948, in conjunction with approximately 30 local artificial eye services throughout the country. With the current scale of demand, services are under significant pressure. Manufacturing delays as well as necessary repainting to obtain adequate colour matching, may severely impact a patient’s rehabilitation pathway to a normal home, social and work life. However, advances in technology mean alternatives are now possible. The aim of this study is to establish the feasibility of conducting a large-scale study of the effectiveness and cost-effectiveness of digitally printed artificial eyes compared to hand-painted eyes. Methods: A cross-over, randomised feasibility study evaluating a digitally-printed artificial eye with a hand-painted eye, in patients aged ≥18 years with a current artificial eye. Participants will be identified in clinic, via ophthalmology clinic databases and two charity websites. Qualitative interviews will be conducted in the later phases of the study and focus on opinions on trial procedures, the different artificial eyes, delivery times, and patient satisfaction. Discussion: Findings will inform the feasibility, and design, of a larger fully powered randomised controlled trial. The long-term aim is to create a more life-like artificial eye in order to improve patients’ initial rehabilitation pathway, long term quality of life, and service experience. This will allow the transition of research findings into benefit to patients locally in the short term and National Health Service wide in the medium to long term. ISRCTN registration: ISRCTN85921622 (17/06/2021)

Fully Transparent and High‐Performance ε‐Ga2O3 Photodetector Arrays for Solar‐Blind Imaging and Deep‐Ultraviolet Communication

With the development of new broadband semiconductor materials and the expansion of solar‐blind deep‐ultraviolet (SBDU) optoelectronics, the demand for high‐performance fully transparent array integration has also increased. Herein, metal–semiconductor–metal (MSM)‐type fully transparent SBDU photodetector arrays (PDAs), based on commercially available ε‐Ga2O3 films, are constructed using indium tin oxide (ITO), indium gallium zinc oxide (IGZO), and aluminum zinc oxide (AZO) transparent conductive oxides as electrodes. The experimental results show that the overall performance of the fully transparent SBDU PDAs used in this study places them at the forefront of ε‐Ga2O3‐based photodetectors (PDs). All three PDs not only exhibit ultra‐high responsivity (286.2, 284.1, and 262.1 A W−1), remarkable detectivity (4.73 × 1014, 5.06 × 1014, and 2.16 × 1015 Jones), and excellent stability, but also fast photoresponse time (5.6/7.2, 6.9/9.5, and 70/200 ms). It is found that the resistivity and carrier concentration of transparent conductive oxides significantly influence device performance. Consequently, it is demonstrated, for the first time, that fully transparent ε‐Ga2O3‐based SBDU PDAs can be used as ultraviolet imagers and signal receivers integrated into a homemade solar‐blind ultraviolet communication (SBUC) system to transmit text data. These results indicate great potential for future applications of fully transparent ε‐Ga2O3 thin‐film solar‐blind photodetectors in next‐generation artificial intelligence eyes, smart windows, light field cameras, and solar‐blind imaging, among others.

Apposition compound-eye image scanner by glass plate optics.

We propose a design approach for a thin image scanner using the concept of an apposition compound eye comprising many imaging units that take only one pixel image. Although light shielding between adjacent imaging units is always one of the main issues for an artificial compound eye, a simple plane structure using three aperture array layers on two glued glass plates prevents such stray light. Our prototyped scanner, with only 6.8-mm thickness as a packaged module, has 632 microlenses with 200-dpi resolution, resulting in a field of view of 80 mm. The evaluated images show no ghost images.

Life Histories of Theban Tombs: Transdisciplinary Investigations of a Cluster of Rock-Cut Tombs at Sheikh ‘Abd al-Qurna Edited by Andrea Loprieno-Gnirs (AUC Press Archaeological Reports). Cairo: American University in Cairo Press 2021. Pp. 200. $79.95. ISBN 9781617979910 (paper).

<i>Life Histories of Theban Tombs: Transdisciplinary Investigations of a Cluster of Rock-Cut Tombs at Sheikh ‘Abd al-Qurna</i> Edited by Andrea Loprieno-Gnirs (AUC Press Archaeological Reports). Cairo: American University in Cairo Press 2021. Pp. 200. $79.95. ISBN 9781617979910 (paper).

The effects of hydroxyapatite implantation with the autogenous sclera cap: A cohort study

We performed a novel hydroxyapatite (HA) prosthesis implantation method in which an HA implant was implanted into the scleral shell with an autogenous scleral cap.Twenty-six patients who had undergone the novel HA prosthesis implantation method and 32 patients who had undergone traditional HA prosthesis implantation were retrospectively reviewed. The postoperative activity of the artificial eye was measured by the Hirschberg test combined with arc perimetry. The visual analog score (VAS) was used to evaluate 2-month postoperative pain and 2-month postoperative discomfort. HA implant vascularization was measured with enhanced magnetic resonance imaging (MRI) 2 and 6 months after the operation. The enhancement volume (VE) and the volume of the HA implant (VHA) were measured. All cases were followed up for 2 years. Measurement data were processed using SAS 6.12.There was a statistically significant difference (P = .016) between the percentages of excellent grade in the two groups. Two months after implantation, the median pain scores of the study and control groups were 2 and 2.5, respectively, and there was a statistically significant difference (W = 585.0, P = .004); there was a statistically significant difference (W = 535.5, P = .000) between the median discomfort scores of the study group (score = 1) and control group (score = 2); the mean VE/VHA values of the study and control groups were 0.3075 and 0.1535, respectively, and there was a statistically significant difference (t = −8.196, P = .000). Six months after implantation, the VE/VHA values of the study and control groups were 0.9686 and 0.5934, respectively, and there was a statistically significant difference (W = 549.0, P = .000). Within 2 years of postoperative follow-up, there were no serious complications in the study group.In the study group, in which the hydroxyapatite implant was implanted into a preserved scleral shell with unaltered muscles and covered with an autogenous scleral cap, postoperative activity and the fibrovascularization of the HA implant were significantly increased, and postoperative pain and discomfort were significantly reduced.

A wide-field and high-resolution lensless compound eye microsystem for real-time target motion perception

Optical measurement systems suffer from a fundamental tradeoff between the field of view (FOV), the resolution and the update rate. A compound eye has the advantages of a wide FOV, high update rate and high sensitivity to motion, providing inspiration for breaking through the constraint and realizing high-performance optical systems. However, most existing studies on artificial compound eyes are limited by complex structure and low resolution, and they focus on imaging instead of precise measurement. Here, a high-performance lensless compound eye microsystem is developed to realize target motion perception through precise and fast orientation measurement. The microsystem splices multiple sub-FOVs formed by long-focal subeyes, images targets distributed in a panoramic range into a single multiplexing image sensor, and codes the subeye aperture array for distinguishing the targets from different sub-FOVs. A wide-field and high resolution are simultaneously realized in a simple and easy-to-manufacture microelectromechanical system (MEMS) aperture array. Moreover, based on the electronic rolling shutter technique of the image sensor, a hyperframe update rate is achieved by the precise measurement of multiple time-shifted spots of one target. The microsystem achieves an orientation measurement accuracy of 0.0023° (3σ) in the x direction and 0.0028° (3σ) in the y direction in a cone FOV of 120° with an update rate ~20 times higher than the frame rate. This study provides a promising approach for achieving optical measurements with comprehensive high performance and may have great significance in various applications, such as vision-controlled directional navigation and high-dynamic target tracking, formation and obstacle avoidance of unmanned aerial vehicles.

Bioinspired Anti‐Fogging and Anti‐Fouling Artificial Compound Eyes

AbstractCurved artificial compound eyes (ACEs) attract enormous research interest owing to their potential applications in medical devices, surveillance imaging, target tracking, and so on. However, fog, dust, or other liquids are likely to condense on the device surface under a humid, low‐temperature environment or outdoors, thus affecting the optical performance. In this work, a multi‐functional ACE (MF‐ACE) is fabricated by a combination of i) femtosecond laser wet etching, ii) soft lithography, and iii) polydimethylsiloxane (PDMS) swelling methods. The fabricated device is close‐packed with over 3000 microlenses (≈108 µm diameter and ≈15 µm height) on a spherical macrolens (6.56 cm diameter and 0.87 cm height). The trapped silicone oil in the cross‐linked PDMS endows the as‐fabricated ACE with excellent water repellence and anti‐fogging, anti‐fouling, and self‐cleaning abilities. In addition, the ACE shows high optical performance and the ommatidia have a spatial resolution of 50.8 lp mm−1. The imaging and focusing experiments demonstrate its high optical properties and uniformity. It is anticipated that this research may provide useful guidelines for the fabrication of anti‐fogging and anti‐fouling optical devices, and such device enables potential applications in autonomous vehicles, medical, or vision systems under harsh environmental conditions.

A force measurement platform for a vitreoretinal surgical simulator using an artificial eye module integrated with a quartz crystal resonator

To provide quantitative feedback on surgical progress to ophthalmologists practicing inner limiting membrane (ILM) peeling, we developed an artificial eye module comprising a quartz crystal resonator (QCR) force sensor and a strain body that serves as a uniform force transmitter beneath a retinal model. Although a sufficiently large initial force must be loaded onto the QCR force sensor assembly to achieve stable contact with the strain body, the highly sensitive and wide dynamic-range property of this sensor enables the eye module to detect the slight forceps contact force. A parallel-plate strain body is used to achieve a uniform force sensitivity over the 4-mm-diameter ILM peeling region. Combining these two components allowed for a measurable force range of 0.22 mN to 29.6 N with a sensitivity error within −11.3 to 4.2% over the ILM peeling area. Using this eye module, we measured the applied force during a simulation involving artificial ILM peeling by an untrained individual and compensated for the long-term drift of the obtained force data using a newly developed algorithm. The compensated force data clearly captured the characteristics of several types of motion sequences observed from video recordings of the eye bottom using an ophthalmological microscope. As a result, we succeeded in extracting feature values that can be potentially related to trainee skill level, such as the mean and standard deviation of the pushing and peeling forces, corresponding, in the case of an untrained operator, to 122.6 ± 95.2 and 20.4 ± 13.2 mN, respectively.

Artificial Eye - Boost to Life

Artificial Eye - Boost to Life