The phenomenon of welding flash eye pain in the middle of the night is a typical manifestation of electro-optical ophthalmia, which is mainly caused by corneal epithelial damage. In the process of welding, welding arc light has strong ultraviolet rays, ultraviolet stimulation may lead to different degrees of damage to the patient’s eyes, for example, may make the epithelial cells of the conjunctiva and cornea appear pitting off, and in severe cases, the tissue will be necrotic, which will stimulate the nerve endings of the eyes, which will lead to the patient’s pain, photophobia and other uncomfortable symptoms. Photoelectric ophthalmia usually appears a few hours after the eyes come into contact with the welding arc light, so after the welding flash, usually at night there will be uncomfortable symptoms, such as tearing, eye redness and swelling, photophobia, vision loss, eye pain, difficulty in opening the eyes and other phenomena. It is recommended that patients with electro-optic ophthalmia consult a doctor in time to assess their condition and follow the doctor’s instructions to choose the appropriate treatment.