TOKYO -- A Japanese company has developed disposable contact lenses that can not only correct vision but also release drugs in the wearer's eyes gradually over 10-15 hours, AFP quoted a chief researcher as saying Thursday.

The lens, developed by major contact lens maker Seed Co. Ltd., raises the possibility of freeing up hayfever sufferers from itchy eyes or putting a "Band-Aid" on the eyes for a quicker recovery from eye surgery.

A research team led by Takao Sato succeeded in making a lens with a special polymer gel, or highly elastic plastic that holds a lot of water, and which can contain drugs.

They aim to commercialize the lens in about five years in cooperation with pharmaceutical firms. "When worn, the lens starts releasing drugs in a chemical reaction with substances in tears ... In exchange, some ionized molecules originally in tears slowly enter the lens in order to prevent them from shrinking," Sato said.

The most difficult problem to overcome in the development was to keep the transparency and shape of the lens, he said, adding researchers were still considering which drugs they should put in the lens.

"It is not a decision yet, but drugs for pollen allergy are a possibility," Sato said.

"We started the development to save pollen allergy sufferers from the trouble of taking out their contact lenses every time they apply eye drops," he said.

Some 13 million Japanese, more than 10 percent of the population, suffer the unique kind of hay fever caused by "sugi" or Japanese cedar trees.

"Another possibility would be post-surgery drugs for cataract patients to help them recover more quickly, just like you apply a sticking plaster to a cut," he said.

A cataract is an eye condition in which opaque spots form in the lens.

Drug-releasing plastic inserts for patients of glaucoma, an eye disease that can result in blindness have already been developed, but they have no optical corrective function and were taken off the market a few years ago because of the discomfort they cause the user, according to Sato.