Could be occular migraines - that is one of several visual symptoms you could have, others being auras and waivy lines and dark holes in the center of the field of vision. Photosensitivity, too, bright light can seem very bright.

Occular migraines are like "Migraine Lite" - they don't have the head pain of a full migraine, but the visual symptoms, and may have other symptoms like weakness, fatigue, nausea, dizzyness.

Had them for years - they are overall harmless, and usually just treated with OTC meds like Excedrin Migraine - but you can get a presciption if they are bad.

Good luck.