Low Vision is a sight condition that causes loss of full sight and that is unfixable by prescription eyewear or surgery. Individuals with Low Vision are not completely blind, but experience severe blind spots, inability to see at night, and extreme sensitivity to glare. According to the American Optometric Association, there are two main categories of Low Vision:
- Partially Sighted: Persons who fall under this category possess visual acuity between 20/70 and 20/200 with conventional prescription lenses.
- Legally Blind: Persons who fall under this category possess visual acuity no better than 20/200 with conventional correction and have a restricted field vision of less than 20 degrees.
Types of Low Vision
While there are two main categories of Low Vision eyesight, there are several types of this condition. The most common types include the following:
- Loss of central vision – when there’s a blind spot in the center of an individual’s vision
- Loss of peripheral vision – when an individual is unable to see to the right and left, above, and below the eye, but can still see from their central vision
- Night blindness – when individuals can see well in daylight, but poorly in dim or dark light
- Blurred vision – when individuals experience foggy vision of objects both near and far away
- Hazy vision – when individuals view everything as though it were under a film or glare
What Causes Low Vision?
Low Vision Eyesight can be the result of many conditions and injuries. Age-related disorders, such as macular degeneration, glaucoma, and cataracts, often contribute to Low Vision, so it’s not unusual to see this issue in adults above the age of 45. Some other common causes include diabetes, cancer of the eye, albinism, and brain injuries.
Low Vision Exams
A Low Vision optometrist will perform a specialized low vision exam to help determine if an individual suffers from this condition. This Low Vision specialist will conduct a functional eye examination that includes the use of special low vision eye charts, lighting tests, magnifiers, and visual acuity, depth perception, and field tests to determine how the patient’s daily life is or has been affected by vision restrictions. Once the level of Low Vision has been detected, Low Vision optometrists can prescribe and educate patients on how to use Low Vision aids to enhance their everyday vision.
Common Low Vision aids include:
- Special optical devices: Magnifiers, mini telescopes, and video lenses that help to enlarge text, tiny objects, and pictures
- Nonoptical solutions: Modifications to a patient’s environment, including better and/or more specific lighting, larger print on reading materials, and the use of specific colors to improve overall sight
- Adaptive daily living equipment: Talking or high-contrast watches and clocks, closed-circuit television, writing guides, and other tools to make everyday tasks easier