What is Low Vision?

Low vision is visual impairment that cannot be corrected by glasses, surgery or medical treatment.

Most people are familiar with the term 20/20 but may not understand what this means and how it relates to someone with macular degeneration. The term 20/20 refers to the eye chart test which determines one's visual acuity.

A visual acuity test checks one's ability to see rows of letters compared to what is considered "normal vision" at the same distance. When the eye chart test is taken, the patient is positioned 20 feet away from the chart ( or it may be adjusted to less by adjusting the letters).

Starting with the row of letters with the largest size, the letters are identified. With each row, the letters get smaller. The eye care professional determines the smallest size letters that are able to be seen with clarity.

If the smallest row of letters that can be seen at twenty feet can be read by someone with normal vision at 60 feet, the uncorrected vision is 20/60.

Of course as we age, very few people have 20/20 vision. Prescription glasses can provide us with corrected vision - which means that with the right prescription glasses one can see at 20/20 or close to it.

If a person's corrected vision is 20/20 they do not have low vision. According to the University of Michigan Kellogg Eye Center, "Low vision is a term that denotes a level of vision that is 20/70 or worse and cannot be fully corrected with conventional glasses."

This low level of vision does significantly interfere with performing everyday activities, but it is not blindness. Along with loss of visual acuity, there can be a loss of field of vision, distorted vision, and a loss of contrast sensitivity.

Those with low vision still have some usuable vision and with the help of vision aids, magnifiers, and rehab, they can perform many of the same activities they did before.

To learn more about how one can maximize their usable sight with low vision aids or through low vision rehab click here:

Low Vision

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Leslie Degner, RN, BSN

Better Health for Better Vision