The brown light reflection in the anterior chamber of the ocular lens is thought to be a mercury lensitis caused by mercury deposition, which can persist after the symptoms of poisoning disappear or after removal from mercury exposure, and is another marker of mercury absorption and a diagnosis of chronic mercury poisoning. What are the symptoms that are easily confused? Acute mercury poisoning is mainly caused by oral administration of mercury compounds such as ascending mercury. Patients suffer from acute corrosive stomatitis and gastroenteritis within minutes to tens of minutes after ingestion. Patients complain of burning pain in the mouth and throat, as well as nausea, vomiting, and abdominal pain, followed by diarrhea. The vomitus and stool often contain bloody mucus and exfoliated necrotic tissue. Patients may often have peripheral circulatory collapse and gastrointestinal perforation. Acute renal failure may occur after 3 to 4 days (in severe cases within 24 hours). There may also be liver damage. Inhalation of high concentrations of mercury vapor can cause fever, chemical tracheobronchitis and pneumonia, respiratory failure, and acute renal failure. Skin contact with mercury and its compounds can cause contact dermatitis, which is metamorphic in nature. The rash is an erythematous papule, which may fuse into patches or form blisters, with pigmentation after healing. Mercury ions are easily combined with sulfhydryl groups, causing the inactivity of cytochrome oxidase, pyruvate kinase, succinate dehydrogenase, etc. Mercury also combines with amino, carboxyl, phosphoryl groups and affects the activity of functional groups. The epithelial cells of the tubule are predominant, and mercury can also cause immune dysfunction, autoantibodies and nephrotic syndrome or glomerulonephritis.