The cornea is the transparent front part of the eyeball. It doesn't contain blood vessels and belongs to the outer fibrous tunic. It represents the first obstacle on which light rays are refracted and focused. It is built of 5 layers, each of which has its own role in maintaining the transparency. Inflammation of the cornea is called keratitis. Symptoms that indicate keratitis are redness, pain, discomfort, itching, epiphora, photophobia, and blurred vision. Keratitis can be of infective and noninfective etiology. Infective causes are bacteria, viruses, fungi and protozoa. Noninfective keratitis is less common, and some of the better known are PUK, VCK, and flictenulosis. They should be distinguished from infective ones, and a good anamnesis can help us to find out the circumstances under which the disease appeared. In addition to the anamnesis, a clinical examination is also important. First, visual acuity is examined, which can be used to determine the preservation of visual function. After that, the eye should be examined with a biomicroscope, which can detect various pathological changes in the cornea. Keratitis can be diagnosed based on the clinical picture, but laboratory and other diagnostic methods should be used to differentiate certain types. Therapy depends on the cause of keratitis and is based on the prevention, stopping of progression and treatment of complications. For most noninfective keratitis the therapy is topical. Severe forms of keratitis require systemic administration of drugs, and some forms require surgical treatment. With timely treatment, noninfective keratitis can be cured and thus prevent serious complications of visual impairment and even blindness.