REGIS Philbin, who was complaining on the air this week about “seeing double,” told viewers yesterday that his condition is due to a weak eye muscle.

“It’s a temporary weakness of one of the eye muscles,” Philbin said to guest co-host Lisa Rinna on yesterday’s “Live with Regis & Kelly.“

Philbin said his doctor, a neuro-opthalmologist, told him the double vision is caused by the closure of a small blood vessel in his eye.

Ordinarily, “normal function” returns in about six to eight weeks – “but sometimes this is the one that doesn’t come back,” he quoted his doctor as saying.

Then surgery is usually suggested, he said.