What does having 20/50 vision (both eyes) mean?

Uncorrected?: If you have a need for eyeglasses, then 20/50 uncorrected is the vision level without glasses. If this is the best with correction then you have some decrease in vision which needs evaluation. The vision fraction, 20/20 indicates a letter of a certain size that can just be seen at 20 feet by a "normal" eye. 20/50 means a larger letter which a normal can see at 50 feet.