Juvenile macular dystrophy (JMD) is the term for several inherited eye diseases that cause loss of central vision in children and young adults. These diseases cause damage to the macula, the area of the eye responsible for central vision. People with macular dystrophies have trouble seeing straight ahead. The most common form of JMD is Stargardt disease, symptoms of which include gray or black spots in the central vision and affect both eyes. Loss of vision occurs gradually at first, but visual loss becomes much more rapid after a certain point. Color vision is affected later in the disease. The second most common form of JMD is Best disease. Symptoms of Best disease usually show up between 3 to 15 years of age. The third most common for of JMD is juvenile retinoschisis, which occurs primarily in young males. Symptoms of juvenile retinoschisis include difficulty focusing both eyes on one object and involuntary eye moments. Vision loss gets worse with age. Unfortunately, there are no treatments available for JMD at this time. However, promising new research is currently being conducted.