A: Lazy eye or “amblyopia” affects approximately 3 percent of young children, and it can be hereditary. Amblyopia occurs when vision is reduced in one eye compared to the other due to differences in focusing ability or alignment (e.g., crossing) of the eyes. As a result, the stronger eye takes over and weaker eye tends to wander. Although in newborns it’s normal to notice an eye wandering, by 4 months of age a child’s eyes should be focusing together.

You may notice the lazy eye by looking at your child, often later in the day, or you may just notice it in photos. It’s important for parents and doctors to identify and treat lazy eye early in childhood, ideally between 6 months and 2 years of age. This is not just for the child’s appearance, but for the child’s vision. The weaker eye needs to be strengthened or else the child can lose vision in that eye, and also lose depth perception. In general, the younger the child is when the problem is identified, the shorter the treatment. After 6 years of age, treatment is less likely to be successful.

Traditionally, the treatment has been to place a patch over the good eye to force the weaker eye to work harder. The treatment typically takes from four to six months, though it’s sometimes shorter or longer. Although many children don’t complain about wearing the patch, many families have trouble getting their child to use it as prescribed because children can find it irritating and embarrassing. Glasses, eye exercises and surgery are sometimes necessary as well.

Recent studies have found that prescription eye drops with atropine are as effective as using an eye patch. The atropine drops put in the strong eye, either daily or once or twice a week, dilate the pupil and blur the vision in the strong eye, forcing the weaker eye to work harder. Most children were successfully treated within six months, and most parents reported that they were able to follow the treatment as prescribed.

Talk with your son’s ophthalmologist about the options.