What is low vision?
Low vision is a permanent visual impairment that you can’t correct with glasses, contacts or surgery. Most eye doctors define low vision as moderate to severe visual impairment — enough to inhibit your everyday activities, like driving and reading.
Terms like “partially sighted” and “legally blind” fall under the larger heading of low vision. But these terms also have more specific meanings. In the U.S., these refer to whether you qualify for special education or disability services for visual impairment.
Low vision may involve a variety of different types of visual impairment; not just nearsightedness or farsightedness, but also peripheral vision loss, a blind spot or blurred vision. You might have OK vision in some ways but still have low vision overall.
Low vision isn’t total blindness — some vision remains. Vision rehabilitation services help people with low vision make the most of what they’ve got. A specialist can help connect you with low vision aids and assistive technology to make your life easier.
What qualifies as low vision on a visual acuity test?
The standard visual acuity test in the U.S. is the Snellen eye chart. It measures the clarity of your vision at a distance of 20 feet from an object. If you have 20/20 vision, which is the average score, it means you can see an object clearly from 20 feet away.
If your score is 20/70, it means that your vision at 20 feet is like normal vision at 70 feet. The World Health Organization (WHO) classifies this score as moderate visual impairment or moderate low vision. A score of 20/200 or above qualifies as severe low vision.
But this isn’t the only score eye specialists consider. Other types of tests measure other aspects of your vision. For example, a visual field test measures your range of vision from side to side. Having a visual field of 20 degrees or less also qualifies as low vision.
Some people have low scores on vision tests, but they’re able to correct their impairment with glasses, contacts or surgery. If these treatments make your test scores go up, you don’t have low vision. Low vision is a condition you have even with your glasses on.
