Lying in bed, eyes closed, cough, and I can see white lights at the corner of both eyes. Is it normal or should I get checked? (Retina detached once)

See ophthalmologist. This is usually the result of the vitreous (jelly portion of the inside of the eye) pulling on retina and causing bright light flashes. In view of your history of retinal detachment, you should see your ophthalmologist.