Learn about Nearsightedness2 . . . The retina may be sufficiently thinned to make retinal tears more likely and periodic retinal examination should be part of a comprehensive preventive eye care routine. Contact lens comfort due to thickness is not usually a problem, as it is with higher degrees of nearsightedness. Problems such as glaucoma have some increased possibility of occurring in association with nearsightedness and should be checked for as part of a regular eye examination. Radial keratotomy is also performed, though its best range is probably no more than about 1 to 3 diopters.
Glasses significantly minify images.
In this range there is absolute glasses dependence at virtually all times. Even reading is awkward without glasses because the reading material must be held so close. Special lenses with high index of refraction, meaning that bend light more per unit thickness than conventional lenses may be needed. Though costly, they greatly reduce the necessary thickness. In addition to making images smaller glasses in this range start to cause additional problems whenever looking outside the very center of the lens, with prismatic distortion, meaning images being optically displaced to the side.