Visual impairment (VI) can be defined by any kind of vision loss that is not correctable, whether it’s someone who is completely blind-cannot see at all or someone who has partial vision loss. Having partial vision loss mean a number of different things to different people. Being visually impaired does not always mean a person does not see anything. Many people with visual impairments can see but have different conditions that impair their vision in different ways. Blindness is not absolute; it is a spectrum.
A few important definitions can be helpful to understand different ways a person can be visually impaired such as:
Complete Blindness
Refers to when a person has a lack of vision or the ability to detect light. Sometimes referred to as no light perception (NLP).
Light Perception Only (LPO or LP)
Refers to when a person has a lack of vision with the ability to detect light. Individuals with LPO may have the ability to detect the brightness of lights, but do not have the ability to detect where the light source is coming from or the color of the light. They will only be able to detect the difference between light and dark.
Legally blind
Your vision is uncorrectable with an acuity of 20/200 or less in your better eye or your field of vision is less than 20 degrees. That means if an object is 200 feet away, you have to stand 20 feet from it in order to see it clearly. But a person with normal vision can stand 200 feet away and see that object perfectly.
Visual field
The entire area that can be seen when the eye is directed forward, including that which is seen with peripheral vision. A healthy total visual field is approximately 190 degrees.
Visual field loss
Visual field loss is when you have lost an area of vision in your visual field.
Tunnel Vision
Tunnel vision is another name for severe peripheral vision loss. It’s called tunnel vision because your ability to see can seem like you’re looking into a tunnel. With tunnel vision you can only see what’s right in front of your eyes.
Central Vision Loss
Central vision loss can appear gradually or suddenly and usually appears as a dark spot, blurred area or distorted area in the center of the visual field. This vision loss makes it to where you cannot see anything directly in front of you but only in the side visual fields.
Low Vision
Moderate to severe vision impairments that effect everyday life that is not correctable with glasses, contacts or any other medical intervention. Being low vision is also a large spectrum of visual difficulties.
Discover a world of possibilities
With the knowledge of these terms, we hope this will help you better recognize when others may be struggling with visual impairments. If you or someone you know, whether it is a family member, friend, student, or co-worker, is struggling with visual impairments and need services to help gain independence, learn braille, make sure the workplace is accessible, and so much more, please reach out to Vis-Ability for help!
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