Some children and adults suffer from a “lazy eye,” but what does that actually mean? The term
“lazy eye” can sometimes become a generalized term for a variety of signs/symptoms. Are the eyelids drooping or do the eyes appear to be crossed? Are one or both eyes unable to see at the standard vision goal of 20/20? The discussion below addresses common misconceptions surrounding the term “lazy eyes.”
Amblyopia, or lazy eye, is diagnosed when there are one or two eyes that have a decrease in
vision (less than 20/20), and is usually developed before the age of 6. Amblyopia occurs when
central vision is lost or lacks in development due to a variety of factors, while peripheral vision is not affected. Central vision is compromised when a blurry image is formed on the back of the eye, known as the retina, or if dissimilar, blurry images are formed between the two eyes during the sensitive period of visual development, between birth and the age of 6. Blurry or dissimilar images may form on the retina when there is a large difference in the degree of nearsightedness or farsightedness between the two eyes, when there is a large amount of astigmatism, when the eyes are crossed, or if there is a barrier to clear vision, such as cataracts or a large droopy eyelid.
Chances for the development of clear vision can be increased with early diagnosis of
amblyopia. The American Optometric Association recommends comprehensive optometric
examinations by the age of 6 months and again at age 3 to monitor for development, before the
crucial age of 6. Treatment is often less effective and longer when the age of diagnosis is at a later age. Treatment for amblyopia may include a combination of prescription lenses, prisms, vision therapy and/or eye patching. Some patients may choose to undergo vision therapy, which includes training of the eyes to work together more effectively. The training can help to prevent and remediate the lazy eye.
Crossed eye, or strabismus, is another term that is often incorrectly interchanged with the general term “lazy eye.” Strabismus is an eye condition where one eye appears to be either turned in or out, giving the appearance of “crossed” or “walled” eyes. Strabismus is an eye condition that can occur when there are problems with the eye muscles, problems with the nerves that send information to the muscles, or if there are problems with the control center in the brain that controls eye movements. Strabismus can also occur with some general health conditions or eye injuries. Having an eye that is turned can keep that eye from forming a clear image, leading to the development of amblyopia, or lazy eye. To learn more about strabismus, please click here.
Like crossed eye, or strabismus, an eye with an upper eyelid droop is often inaccurately coined as the “lazy eye.” A lid droop of the upper eyelid is called a ptosis (TOE-sis) and can occur in both children and adults. When the lid is drooping severely, a ptosis can cause difficulty seeing. If there is a severe eyelid droop that blocks central vision in an eye and is not corrected before the sensitive period of visual development, poor vision can occur, leading to amblyopia.
The importance of early comprehensive optometric examinations is crucial to monitor for healthy
development of the eyes. Eye care practitioners can check for any anomalies that might lead to
amblyopia, and can further treat and manage conditions such as amblyopia, strabismus, and ptosis to ensure and maintain the best chances at having clear vision.