Can a person keep his glasses on while going for mri (magnetic resonance imaging)?

Sometimes. As long as there is no ferromagnetic metal in the frame.
Why would you. The technicians running mris wil require you to take all metal containing objects out of the room while you have your scan. This will include your glasses. There is little to see when you are in the scanner anyway and you will be given your glasses immediately when it is over. Let the experts manage things for you.