Legal Blindness is a pretty strong term. If you see my son out playing you might think he’s not blind at all. There are a lot of factors that play into the diagnosis and severity of vision impairment. Your standard eye chart goes much further than you’ve likely ever needed. But how can someone be diagnosed as blind and have vision?
When Ollie was born his eyesight was labeled worse than a profound visual impairment. He could see directly in front of his face and with great difficulty. Because he had some sight 20/2400 right and 20/4800 left he was not blind. Complete blindness is incredibly rare and more often a result of injury or loss.
You’ve seen the Snellen Eye Chart. The very top E from the chart is the vision of someone legally blind. This does not take into account central vision which I will further explain. Put in the simplest terms that is the smallest size someone legally blind can see from 20 feet. It shows that someone with the qualifier of legal blindness still has a valid range of sight.
If you don’t need lenses you have perfect vision. Even if you need prescription glasses whatever the lens corrects to is your visual acuity. Vision impairment is the best that person can see with correction. Corrective lenses are pretty standard and unless your vision is worse than 20/70 you are not visually impaired.
Moderate Vision Impairment is from 20/70 to 20/160. Those with moderate vision impairment might need to read larger print, and have a few adaptations but can drive and interact as normal. You would qualify for an IEP or similar adaptations in your schooling and accommodations for work.
Severe Vision Impairment is 20/200 to 20/400. This is legal blindness. The legal aspect implies that lawfully this person is incapable of driving, or similar tasks, and qualifies for help from Services to adapt those needs. It’s a pretty strong term but doesn’t quantify what that person can see. My son can see peripherally but does not have fine detail or depth perception. The lack of depth perception is the main reason my son uses a white cane. The white cane is an extension of the person. Treat that cane as you would treat the person. I will certainly follow this up with advice on how to treat someone using a cane.
Most likely the person quantified as legally blind does not have much vision outside of 20 feet, this is in general and I am not saying there aren’t those that do. Consider a fast moving car in a residential area, my son would have trouble discerning where that car was if he relied on sight alone. I will let you imagine the daily trouble this can cause with those that are unaware.
Severe Vision Impairment is from 20/500 to 20/1000. This is pretty severe and equates roughly to 10 feet. Remember that this does not tell you what that person can see. In my child’s case he was below this line. What do they call vision after this line? Barely Sighted, meaning my son could see something, anything, at all. There is very little quantification after this. At least to my knowledge.
Legal Blindness and beyond are not a death sentence to normality. My child does what other children do with some modification and sometimes delays, but he can still do it. Nothing is impossible. Given access to resources and those that can help the person adapt, everything is possible.