The cornea and lens are also responsible for focusing incoming light on to the retina to create a clear image. To work properly, the cornea needs to be perfectly curved, like the surface of a football. However, in astigmatism the cornea is shaped irregularly, like the surface of a rugby ball.
Celiac disease. Celiac disease is an autoimmune disease in which people canât eat gluten because it will damage their small intestine. If you have celiac disease and eat foods with gluten, your immune system responds by damaging the small intestine. Gluten is a protein found in wheat, rye, and barley.
1 Celiac is also linked to other autoimmune disorders and is now believed to lead to osteoporosis, anemia, infertility and cancer if left untreated.  Inheritance: the genetics of Celiac disease is simplest of the automimmune diseases, with autosomal recessive inheritance and an environmental factor, gluten.