A score of 20/20-2 means you read almost every letter on the 20/20 line of the eye chart but missed two. It’s a precise way your eye doctor records just how close your vision is to the standard benchmark, and it means your eyesight is essentially normal.
How the Minus Notation Works
During an eye exam, you read rows of progressively smaller letters on a Snellen chart from 20 feet away. Each row corresponds to a visual acuity level: 20/40, 20/30, 20/25, 20/20, and so on. When you can read every letter on the 20/20 line, your vision is recorded as a clean 20/20. But if you get most of the letters right and miss a couple, your doctor doesn’t round down to the next worse line. Instead, they note the line you attempted and subtract the number of letters you missed.
So 20/20-2 means you successfully identified the 20/20 row but got two letters wrong. The same system applies at any level. Someone who reads the 20/40 line but misses two letters would be scored 20/40-2. A plus sign works the opposite way: 20/25+1 would mean you read the entire 20/25 line correctly and also got one letter from the smaller 20/20 line.
What 20/20 Actually Measures
The phrase “20/20 vision” means normal visual acuity. The top number is your distance from the chart in feet (always 20 during the test). The bottom number is the distance at which a person with normal eyesight could read that same line. So 20/20 means you see at 20 feet what a normally-sighted person sees at 20 feet. A score of 20/40 would mean you need to be at 20 feet to read what someone with normal vision could read from 40 feet away.
It’s worth knowing that 20/20 doesn’t mean perfect vision. It only measures sharpness at a distance. It tells you nothing about peripheral vision, depth perception, color vision, or how well your eyes focus up close. Someone with 20/20 acuity can still have other visual problems.
Is 20/20-2 Good Vision?
Yes. Missing two letters on the 20/20 line puts your acuity very close to the standard normal range. For all practical purposes, this is excellent distance vision. It comfortably exceeds the requirements for an unrestricted driver’s license in every U.S. state. All but three states set the minimum at 20/40 in the better eye, and the most lenient states require 20/50 or 20/60. A score of 20/20-2 is far sharper than any of those thresholds, so you would not need corrective lenses to meet driving standards.
Your eye doctor is unlikely to recommend glasses or contacts based on 20/20-2 acuity alone. The difference between 20/20 and 20/20-2 is not something you’d notice in daily life. It wouldn’t affect reading street signs, watching a movie, or recognizing faces across a room. If your prescription says 20/20-2, you can treat it as functionally normal vision.
Why Doctors Use This Level of Detail
The minus notation exists because visual acuity doesn’t always fall neatly on one line. Without it, your doctor would have to choose between recording your vision as 20/20 (slightly generous) or 20/25 (slightly harsh). Neither would be accurate. The minus system gives a more precise snapshot, which matters for tracking changes over time. If your acuity shifts from 20/20-1 to 20/20-3 over a few years, that subtle trend could prompt your doctor to investigate earlier than a jump from one full line to the next would.
This precision is also important in certain professions. Pilots, military personnel, and law enforcement officers sometimes face acuity standards stricter than 20/40, and the difference between 20/20 and 20/20-2 could matter in those evaluations. For most people, though, the distinction is academic.