The diopter is a unit of measurement used to describe how well a person sees.
Farsightedness is measured in positive diopters, and nearsightedness is measured in negative diopters. Astigmatism is measured in diopters that can be either positive or negative.
With diopters, the farther a measurement is from 0, the more severe the refractive error. For example, if a person has -4 diopters of nearsightedness, it means that the farthest point you can see clearly is one-fourth of a meter (about 10 inches) from your eye.
Medical Review:Kathleen Romito MD - Family Medicine & Adam Husney MD - Family Medicine & Christopher J. Rudnisky MD, MPH, FRCSC - Ophthalmology
PeaceHealth endeavors to provide comprehensive health care information, however some topics in this database describe services and procedures not offered by our providers or within our facilities because they do not comply with, nor are they condoned by, the ethics policies of our organization.