Vision and Visual Disability
Vision is the primary sensory modality for humans, accounting for over 80% of sensory input. Visual impairment, also referred to as visual disability, signi cantly affects not only visual function but also the individual's quality of life, contributing to substantial socio-economic challenges.
Visual Disability Overview
Visual disability is broadly categorized into total blindness and low vision, with specific definitions varying according to clinical or functional context.
- Total Blindness generally denotes a complete absence of visual perception, including no light sensitivity.
- Low Vision is de ned as a permanent visual impairment where the best-corrected visual acuity in the better-seeing eye is less than 6/18 (approximately 30% of normal vision).
Individuals with low vision, despite this permanent impairment, retain the potential to improve functional sight through the use of assistive devices or specialized lenses to support daily living activities.
Classification by Severity
According to the World Health Organization (WHO), low vision patients are strati ed into three severity levels—mild, moderate, and severe—based on the functional impact on their daily lives.
This classi cation relies on assessments of the better-seeing (dominant) eye, considering parameters such as best-corrected visual acuity and visual field performance.
The International Classi cation of Diseases 11 (2018) classi cation for distance vision impairment is as follows. For characterizing binocular vision impairment, vision acuity should be measured with both eyes open with presenting correction if any. For characterizing monocular visual impairment, visual acuity should be measured monocularly with presenting correction if any.
SWISSCOAT Low Vision Lens Solutions
SWISSCOAT is committed to offering a comprehensive range of “Low Vision” lens products designed to support patients affected by diabetes, severe myopia, night blindness, and other acquired visual impairments. Our primary approaches to enhancing visual function include:
- Magnification through high-prescription lenses, combined with tailored prism corrections, to facilitate reading and near tasks.
- Low vision rehabilitation utilizing specialized E-Scoop lenses.
- Improvement of image contrast and reduction of photosensitivity using advanced filters to alleviate visual discomfort. Note: Methods 1 and 3 may be applied independently or in combination, depending on patient needs.
SWISSCOAT introduces this dedicated series of functional lenses to help individuals with low vision enhance their sight and visual quality, ultimately improving their daily living and overall quality of life.
Low Vision Lens Product
The SWISSCOAT MED S Low Vision lenses, when used in combination with magnifiers, offer patients an effective solution for close-distance magnifi cation, delivering one of the widest fields of view available among hands-free magnifier options.
These lenses integrate high magnification with specially designed base-in prisms. The prism values are calibrated to maintain a fixed difference of two diopters relative to the refractive power of the lenses. This prism incorporation helps to reduce binocular convergence stress typically experienced during near vision tasks, thereby improving visual comfort and functionality.
MED EVS Lenses
SWISSCOAT’s MED EVS lenses are speci cally designed to enhance the visual performance of patients with low vision, particularly those affected by macular degeneration and scotoma. These lenses incorporate five unique features aimed at maximizing visual function and comfort:
- Special Lens Thickness: Enhances image magni cation to support better detail recognition.
- Custom Filter Tint: Reduces visual stress caused by bright light and provides UV protection, increasing comfort and improving overall vision.
- Lens Curve Options: Strategically designed to magnify images, allowing patients to perceive ner details. Available in +3.00, +4.00, +6.00, +8.00, and +10.00 diopters.
- Base-Up Prism: Redirects light from damaged macular regions to healthier peripheral retinal areas, helping patients with scotomas utilize unaffected parts of their vision. Prism options include 4 , 6 , and 8 .
- Anti-Reflective Coating: Minimizes glare and re ections, enhancing visual clarity especially during night driving.
