What is the name for a lazy eye?

"Lazy eye" is a non-medical word for one or both of two medical conditions: Amblyopia and Strabismus.

Amblyopia is where an eye cannot see (or be given correction to see) the normal 20/20 level of visual acuity. This is typically in an eye which otherwise appears quite normal! The cause is insufficient development of the neural pathways from the eye to the part of the brain that processes images. An analogy might be a two-lane road compared to a 6-lane highway where the former is just not able to carry enough traffic (visual data) to serve the transportation needs of the city the way the latter can.

How could this happen? The most common reason is Strabismus: where the eye muscles are not aligning the eyes properly. In order to avoid seeing double, the body suppresses the full development of one eye's visual capacity during our early growth years.

Another common cause is when one eye is much more nearsighted or farsighted than the other. A person can have both or only one of these conditions but can be described as having a "lazy eye." But that word unfairly insults the work ethic of the eye IMO!

_Written by J. Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic