For children with moderate lazy eye, or amblyopia, wearing an eye patch only two hours a day is as effective as wearing the patch for the standard six hours a day, the study shows.

The new findings, appearing in the May issue of the Archives of Ophthalmology, are expected to improve treatment compliance for children who are reluctant to wear the eye patch during school hours.

Amblyopia develops when the brain favors one eye over the other, causing crossed eyes, wandering eyes, or a large discrepancy between the visual strength of the two eyes. Wearing a patch on the stronger eye forces the brain to work better with the weaker eye.

"The upper and lower limits of eye patching were not known. We found that people were falling back to just a few hours a day because of their busy schedules," said study chairman Dr. Michael Repka, professor of ophthalmology and pediatrics at Johns Hopkins University in Baltimore. "Was it good or bad? We didn't know."

The multi-center trial involved 189 children under the age of 7 who were treated at 32 clinical sites across the country. The children were randomly assigned to either wear the patch for two hours a day or six hours daily for a period of four months. In order to exercise the weaker eye, the children were asked to complete one hour of close-up reading or art work per day.

At the conclusion of the study, the kids were asked to read a standard eye chart and, surprisingly, both groups performed identically.

The results have very practical implications for clinicians and parents who can now adapt and monitor children's compliance with treatment, said Repka.

"Anyone who's tried to get a child to wear a patch over an eye knows that it becomes an emotional issue and a point of contention that can disrupt family life from morning until night," said Dr. David Hunter, chairman of ophthalmology at Children's Hospital in Boston.

But while the findings may help relieve some of the stress for children who rely on patching to correct their vision, it's not likely to replace an alternative eyedrop treatment that has proved attractive to patients and equally as effective as patching, said Hunter.

"There's still children that won't wear the patch no matter what, and that's where the eye drops come in," he said. "I personally treat most of my patients with atropine eye drops. Once the drop is in, you're all set for the day."

Adherence to the eye patching schedule is crucial because treatment for amblyopia must occur in childhood in order to prevent visual impairment in adulthood.

The researchers are now conducting a new study to determine if the scaled-back treatment is also an appropriate option for children with severe amblyopia.

More information

Read about lazy eye and its treatment from the American Academy of Ophthalmology or the National Eye Institute.