Sunlight consists of lights of continuous spectra. Ultraviolet light and blue light in the sunlight have higher energy. High dose exposure to sunlight can cause direct cellular damage. In the eye, sunlight is known to cause pathological changes in various eye structures. We reviewed the studies on the role of sunlight in corneal diseases, cataracts, glaucoma, and age-related macular degeneration in recent years. Possible sunlight-triggered signaling pathways and mechanisms in the eye are summarized. Excessive exposure to sunlight may lead to increased DNA damage, aberrant protein modification and aggregation, and oxidative stress of ocular tissues, and thus results in the development of ocular diseases. Accordingly, physical protection, topical and/or oral antioxidants and small molecules blocking sunlight-activated signal pathways could be used independently or combinedly to prevent and reduce sunlight-induced ocular damages.