To the general public, the transition to a governor who is legally blind has been almost imperceptible because Mr. Paterson, 53, acts in many ways like a person with 20-20 vision.

He does not walk with a cane or read Braille. He threw out the first pitch at a Mets game at Shea Stadium last week. And when he is in the Capitol’s familiar stone and marble corridors, where he has worked for two decades, he walks at a brisk pace, slowing down only when an aide alerts him to someone approaching.

Since he cannot read from a prompter, the governor tries to commit his speeches to memory, by listening several times to an aide’s recording of the speech. Delivering an address just from memory can be nerve-racking.

“It’s like a high wire,” he said. “You trip, there’s no net.”