Usher syndrome is primarily a rare genetic condition that leads to partial or total hearing loss and vision loss that worsens over time.The hearing loss comes from abnormalities in the inner ear, while the vision problems are due to a disease called retinitis pigmentosa, affecting the layer of light-sensitive tissue at the back of the eye.The light-sensing area of the retina gradually breaks down in this condition, with night vision usually being the first to deteriorate, followed by blind spots appearing at the sides of the eyes. Around 4 to 17 people in every 100,000 people are affected by the disease with three different types of Usher syndrome.