If you stare at the light bulb for too long then it could potentially blind you.
However just looking at a light bulb once directly might cause your eyesight to become blurry but it should return to normal soon after.
A light bulb isn't as bright as the sun and doesn't put out as much light as the sun either so it shouldn't harm you but still you shouldn't stare at a light bulb anyway but just looking into a light bulb shouldn't do any harm except cause temporary blurry vision.