Stinging and tearing when looking directly into the sunlight is a very common symptom in ophthalmology, mainly due to the following reasons: 1. It is a physiological phenomenon, if the strong light irradiates the eyes for a long time, it will cause burns to the corneal epithelium and retina, so the eyes will have protective reflexes under normal physiological conditions, and will feel stinging and tearing when encountering direct sunlight, thus making people reflexively avoid damage to the cornea. 2. caused by damage to the corneal epithelium, such as damage caused by pathogens infecting the cornea of the eye, or scratches to the corneal epithelium caused by rubbing the eye and foreign objects entering the eye, can cause reflexive photophobia and tearing of the eye. 3. caused by electrophthalmia, when the eye is exposed to strong sunlight for a long time without protection, it will causes burns to the corneal epithelium, causing photophobia and tearing.