What does 20/20-1 mean?!
Question: What does 20/20-1 mean?
I've been taking eye tests on my iPod because I think I might need glasses, but one time I got 20/40(-1) on the close and 20/20(-1) on the far. What is the negative 1?
Answers:
20/20-1 means you read the 20/20 line, but got one letter incorrect. This isn't that big of a deal, as the size of the letters differ across the line. You can get 3 letters wrong before you drop back to 20/25. In other words, if you read the 20/20 line but get 3 wrong, your vision is still counted as 20/20.
first year optometry student
20/20 that's mad dog