Myopia, or nearsightedness, was a medical condition affecting the sufferer's eyes, causing a decreased ability to focus on objects at long range, and a comparatively better ability to focus on objects at close range. It was the reverse of hyperopia.
The condition could be improved with glasses or artificial lenses.
It was one of a number of handicaps that randomly afflicted Grey Orions, due to their genetic mutilation. (FASA RPG - The Orions module: Book of Deep Knowledge)
Annika Hansen stated in a 2385 interview with Jake Sisko that she believed the Federation Starfleet to have myopia regarding The Doctor's individuality and sentience. (ST website: The Path to 2409)