Lazy eye, or amblyopia, refers to vision loss due to the eye and brain not properly working together despite having a physically normal and healthy eye. Lazy eye can happen to one or both eyes. The most common causes of lazy eye include:
  • an imbalance in uncorrected prescription between the eyes which leads the brain to favor seeing from the ‘clearer’ eye
  • a large uncorrected prescription in both eyes such that the brain doesn’t learn to see ‘clearly’
  • an eye turn of one eye, or both eyes
Although lazy eye is often defined as a loss of visual acuity, i.e. that eye is not correctable to 20/20, there are often other functional vision abnormalities in spatial vision, contrast sensitivity, and impaired stereoacuity. Many people experience crowding phenomenon, a perceptual problem where excess words and clutter can impair one’s ability to recognize the object of interest. Symptoms of difficult reading in a paragraph but not isolated words, clumsiness, visual discomfort when viewing certain patterns, disorganization, and difficulty navigating curves on sidewalks, are common complaints I hear from patients as a result of these functional vision deficits.

Normal Vision Processing

Many people describe vision similar to a camera. The light enters the eye and is projected to the back of the eye similar to the optics of a picture which is reflected onto the film or digital sensor at the back of a camera. However, vision is far more complex. The information from the back of the eye travels to the brain where information from the visual picture is broken down then “sorted”.
Vision is a highly specialized function. For example, information about contour and color i.e. commonly referred as the “WHAT” pathway, is processed in a completely different area of the brain than information about motion and mental representations of object locations, commonly known as the “WHERE” pathway. #Brain&Eye

Lazy Eye Treatment

Treatment often begins with providing the best optical correction. This is true for patients who have lazy eye as a result of prescription imbalances or large uncorrected prescriptions since it can clear the out-of-focus image. Patients with eye turns have frequently been told to patch or penalize their good eye so that their weaker eye can get practice at seeing for short periods of time. In some practices, atropine is used as a pharmacological patch. Over penalizing the good eye however can result in reverse amblyopia.
In this practice, vision therapy is often recommended to help patients actively improve their functional vision skills. In normal individuals, functional visual skills develop naturally through time and life experience. Thus when prescription glasses are the first to give the brain similar images between each eye to fuse, the brain needs time to put the information together efficiently. Therapy can help fast-track the learning process by providing the opportunities to improve specific perceptual, eye teaming, and eye-coordination skills.
There is popular belief that lazy eye treatment is only effective in children. However, since lazy eye is really a brain problem, there is no age that limits when amblyopia treatment can begin. For those interested in learning more about an adult treatment of lazy eye, I would highly reading “Fixing My Gaze” by Sue Barry, a professor who underwent vision therapy and developed the ability to see stereovision for the first time when she was close to 50 years old! See http://www.stereosue.com/
Vision is a learned skill that is not limited by age. As Dr. Streff once said, “When vision is working well-it guides and leads. When it is not, it interferes.”