Can you read the first line of the eye chart? I believe you have heard this question more than once. There are various sorts of eye charts. Some charts make use of graphics, patterns, or letters. However, the most commonly used eye chart was developed by Dr. Herman Snellen, the Dutch ophthalmologist in 1860s.  Dr. Snellen also introduced the eyesight ratio, which we still use these days, the 20/20 vision. A person with 20/20 vision can see a line in an eye chart when standing 20 feet away.

So, what exactly does 20/15 imply? When they are 15 feet away, you can see a line in the eye chart if you have 20/15 vision. When tested at a distance of 20 feet from your eyes, it also suggests you have better than normal eyesight.

PS: Happy Valentine’s Day from us to you.