As the name implies, a “lazy eye” is one that does not take part fully in the seeing process. The images the lazy eye sends to the brain are ignored (suppressed). As a result, only the better eye is used for sight by the brain. If not treated, loss of vision can occur in the lazy eye.
Amblyopia commonly develops in infancy and early childhood and affects about 3% of children. It may develop due to vision conditions such as a crossed or wandering eye (strabismus). Or, it can occur because of unequal vision in the two eyes caused by astigmatism, farsightedness or nearsightedness.
A key to successful treatment of lazy eye is to encourage its use whenever possible. Corrective eyeglasses or contact lenses can sometimes encourage the use of the lazy eye by providing it with the clearest possible vision. Occlusion of the better fellow eye with either patching or blurring eye drops (atropine) can also force the use of the lazy eye. In addition, doing near visual activities with the occlusion, such as reading, using a computer, and playing video games, will stimulate greater use of the lazy eye.
The time period for which patching is recommended depends on the age and vision at presentation. Older age (greater the 8 years) and greater difference in visual acuity (more than 4 lines difference on distance vision testing) warrant longer (6 – 8 hours/day) hours of patching. Hence early intervention is the key to the successful outcome.
Every new patient diagnosed with amblyopia, however, should undergo few months of patching therapy before being declared as refractory.