Definition: Chorioidoiritis is a type of eye disease that affects the choroid, or layer of nerve cells in the retina (eye). It can cause vision problems, such as blurry or double vision. It is often caused by an abnormal cell called a "choroiditis" which is also known as a "choriocytoma". The exact cause of chorioidoiritis remains unclear, but it is thought to be related to autoimmune diseases such as rheumatoid arthritis