The inability to keep your eyes open may be caused by ptosis, or by corneal irritation due to various eye diseases, such as conjunctivitis, keratitis, or a foreign body in the eye, or it may be caused by visual fatigue. If you feel that you cannot open your eyes, first determine whether you have ptosis. There are congenital and acquired factors that cause ptosis, the former is usually considered surgical, the latter may be due to myasthenia gravis, oculogyric nerve palsy, sympathetic nerve disease, blepharitis, cysts that cause eyelid swelling and ptosis, after the cause is clearly identified, the cause needs to be treated and if it is not effective then surgery is considered. If the symptoms of corneal irritation cause the eyes to open and are accompanied by significant redness, swelling, pain, and foreign body sensation, the symptoms should be treated symptomatically and will improve when the irritating factors are removed.