Occasionally a person experiences visual changes that are difficult to completely understand with only a clinical eye exam. These changes may be due to abnormalities in the function of some of the cells on the back of the eye in the retina, or there may be changes in the nerve connections between the eye and the brain.
Worldwide, viral hepatitis is the most common cause of liver inflammation. Other causes include autoimmune diseases and ingestion of toxic substances (notably alcohol), certain medications (such as paracetamol), some industrial organic solvents, and plants. large number of medications and other chemical agents can cause hepatitis. In the United States acetaminophen, antibiotics, and central nervous system medications are among the most common causes of drug-induced hepatitis.
Drugs can cause liver disease in several ways. Some drugs are directly injurious to the liver; others are transformed by the liver into chemicals that can be injurious to the liver directly or indirectly. There are three types of liver toxicity: dose-dependent toxicity, idiosyncratic toxicity, and drug allergy. Drugs that cause dose-dependent toxicity can cause liver disease in most people if enough of the drug is taken. The most important example of dose-dependent toxicity is acetaminophen (Tylenol) overdose.