An ocular manifestation of a systemic disease is an eye condition that directly or indirectly results from a disease process in another part of the body. There are many diseases known to cause ocular or visual changes. Diabetes, for example, is the leading cause of new cases of blindness in those aged 20–74, with ocular manifestations such as diabetic retinopathy and macular edema affecting up to 80% of those who have had the disease for 15 years or more.[citation needed] Other diseases such as acquired immunodeficiency syndrome (AIDS) and hypertension are commonly found to have associated ocular symptoms.