Visual acuity

Visual acuity (VA) commonly refers to the clarity of vision, but technically rates a person's ability to recognize small details with precision. Visual acuity depends on optical and neural factors. Optical factors of the eye influence the sharpness of an image on its retina. Neural factors include the health and functioning of the retina, of the neural pathways to the brain, and of the interpretative faculty of the brain. The most commonly referred-to visual acuity is distance acuity or far acuity (e.g., "20/20 vision"), which describes someone's ability to recognize small details at a far distance. This ability is compromised in people with myopia, also known as short-sightedness or near-sightedness. Another visual acuity is near acuity, which describes someone's ability to recognize small details at a near distance. This ability is compromised in people with hyperopia, also known as long-sightedness or far-sightedness. A common optical cause of low visual acuity is refractive erro

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Visual impairment, also known as vision impairment, is a medical definition primarily measured based on an individual's better eye visual acuity; in the absence of treatment such as corrective eyewea

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Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are indepen

MICRO-722: 3D Printing with light

Optical aspects of 3D printing technology. This includes optical systems for scanning and excitation, photopolymers, glass and other photoactive materials, and optical components fabricated with 3D printing technology.

BIOENG-448: Fundamentals of neuroengineering

Neuroengineering is at the frontier between neuroscience and engineering: understanding how the brain works allows developing engineering applications and therapies of high impact, while the design of new measurement and data analysis techniques contributes to advance our knowledge about the brain.

BIO-480: Neuroscience: from molecular mechanisms to disease

The goal of the course is to guide students through the essential aspects of molecular neuroscience and neurodegenerative diseases. The student will gain the ability to dissect the molecular basis of disease in the nervous system in order to begin to understand and identify therapeutic strategies.

Sutureless ocular surface reconstruction

Basile Salmon

Corneal diseases account for eight million blind people worldwide, making up to 10% of all causes of blindness. As 80% of the information is collected by our senses, blindness is a very invalidating condition which lowers greatly patients’ quality of life. Limbal stem cell deficiency describes all the conditions involving the failure of corneal epithelium and its progressive replacement by conjunctival epithelium and the opacification of the cornea, creating ultimately a loss of vision. Restoring transparency by reconstructing the ocular surface with a healthy corneal epithelium is the only long term treatment of this condition and has been a major challenge for regenerative medicine for the past twenty years. As the understanding of corneal epithelium renewal increases, the solutions offered to restore visual acuity are improving but the long term results of techniques used so far are still poor. We describe here an attempt to fix the issue of inflammation due to sutures in the case of transplantation of limbal epithelial cells carried by an amniotic membrane, by the use of an adhesive. LYDEX, our chemically defined bioadhesive uses food additives as building blocks for the formation of an hydrogel, which has been described to be perfectly bio-compatible. Results of this study confirm the absence of immunological reaction in the presence of our hydrogel but also bring to light its potentially insufficient permeability to glucose, which combined to mechanical trauma, leads to a dramatic failure of the grafted epithelium

2010

Design and validation of a foldable and photovoltaic wide-field epiretinal prosthesis

Marta Jole Ildelfonsa Airaghi Leccardi, Michele Bevilacqua, Naïg Aurelia Ludmilla Chenais, Laura Ferlauto, Diego Ghezzi, Samuel Charles Antoine Gilliéron, Kevin Sivula, Paola Vagni

Retinal prostheses have been developed to fight blindness in people affected by outer retinal layer dystrophies. To date, few hundred patients have received a retinal implant. Inspired by intraocular lenses, we have designed a foldable and photovoltaic wide-field epiretinal prosthesis (named POLYRETINA) capable of stimulating wireless retinal ganglion cells. Here we show that within a visual angle of 46.3 degrees, POLYRETINA embeds 2215 stimulating pixels, of which 967 are in the central area of 5 mm, it is foldable to allow implantation through a small scleral incision, and it has a hemispherical shape to match the curvature of the eye. We demonstrate that it is not cytotoxic and respects optical and thermal safety standards; accelerated ageing shows a lifetime of at least 2 years. POLYRETINA represents significant progress towards the improvement of both visual acuity and visual field with the same device, a current challenging issue in the field.

2018

How do visual skills relate to action video game performance?

Arthur Barakat, Oh-Hyeon Choung, Aline Françoise Cretenoud, Michael Herzog

It has been claimed that video gamers possess increased perceptual and cognitive skills compared to non-video gamers. Here, we examined to which extent gaming performance in CS:GO (Counter-Strike: Global Offensive) correlates with visual performance.We tested 94 players ranging from beginners to experts with a battery of visual paradigms, such as visual acuity and contrast detection. In addition, we assessed performance in specific gaming skills, such as shooting and tracking, and administered personality traits. All measures together explained about 70% of the variance of the players’ rank. In particular, regression models showed that a few visual abilities, such as visual acuity in the periphery and the susceptibility to the Honeycomb illusion, were strongly associated with the players’ rank. Although the causality of the effect remains unknown, our results show that high-rank players perform better in certain visual skills compared to low-rank players.

2021