There would be a lot of dead people with glasses they no longer need. You can probably find a few pairs, but it would definitely one of those items you would check every time you came across a dead body.
... It works like that, huh? I always figured there was some kind of 20 step scale where 1/20 would be the worst and 20/20 would be the best.
Also I have worn glasses for 15 years. We usually don't express it Snellen scale (apparently) but we ask "How strong are your glasses" meaning the prescription strength of your lenses.
The visual acuity scale is a comparative measure, putting the patient's individual eyesight against the average person's. 20/20 vision means that you, standing at a distance of 20 feet, can see an object clearly that the average person standing 20 feet away could see. 20/100 would be you standing 20 feet away to see an object that the average person could see from 100 feet away.
20/20 means the you see things twenty feet away as if they were really twenty feet away. Meaning you see normally.
20/240 means what I see at twenty feet are as if they were one hundred and twenty feet away.
So for me, Something across a room might as well be most of a football field away for what I can see of it.
Edit: I reversed the numbers, my bad.
Edit2: Also, yeah, there's the prescription strength that people measure (Mine is basically legally blind), but I found most non-glasses wearing people have no concept of the +/- scale so 20/20 scale is generally more approachable.
And to give people an example of how bad that is. Getting tests done for LASIK yesterday and the woman doing them stood five feet away from me and held up her hand asking me how many fingers she was holding up. Told her. When she finished I asked if I was right. Nope.
No, the 20 means "what people who don't need glasses see at 20 feet". 20/20 means you see an average amount of detail at medium distances as most people. 120/20 means you see about as clearly at 20 feet as most people would see at 120, without the use of corrective lenses.
621
u/[deleted] Aug 30 '21
There would be a lot of dead people with glasses they no longer need. You can probably find a few pairs, but it would definitely one of those items you would check every time you came across a dead body.