The eyes can not stand the stimulation of bright light, some of which is a normal physiological response, but also may be related to a variety of eye diseases, such as visual fatigue, dry eye, conjunctivitis, keratitis, congenital iris, pupil dilatation, albinism and so on. If strong light is directed to the eye, the pupil will obviously appear to narrow the reaction, and even the phenomenon of tears, the purpose is to reduce the strong light on the retina of the fundus of the persistent light stimulation, is the body’s self-protective reaction. If there are various diseases on the eye surface, especially when there are lesions on the cornea, corneal irritation symptoms will be more likely to occur, manifested as photophobia, tearing and other phenomena. Poor rest, mental stress, and strong nerve sensitivity can lead to significant pain or supraorbital neuralgia after strong light stimulation because the nerves in the cornea are branches of the trigeminal nerve.