Getting up in the morning and seeing black cracks in your eyes can be caused by physiological factors such as staying up late for a long time, or by diseases such as conjunctivitis and mosquitoitis. 1. Physiological factors: If you have been using your eyes for too long, staying up late for a long time, it may cause visual fatigue, leading to black cracks in the morning. It is recommended to reduce the recent eye time, more eye massage, hot compresses, to relieve fatigue. 2. Conjunctivitis: microbial infection, chemical stimulation, physical stimulation and other factors may induce conjunctivitis, so that patients get up in the morning and open their eyes to see black cracks, but also prone to increased eye secretions, eye redness, photophobia and other symptoms. 3. Flying mosquito: age, vitreous blood, retinal cracks and other reasons may induce flying mosquito, resulting in patients to open their eyes in the morning to see black cracks, may also be accompanied by decreased visual acuity, eye flashing sensation and other symptoms. If you see black cracks when you wake up in the morning, we suggest you to go to the hospital and have a relevant examination to clarify the cause of the disease and have it treated as soon as possible after eliminating the physiological factors.