Often there are no symptoms in the early stages of the disease, nor is there any pain. Don’t wait for symptoms. Be sure to have a comprehensive dilated eye exam at least once a year. Blurred vision may occur when the macula—the part of the retina that provides sharp central vision—swells from leaking fluid. This condition is called macular edema. If new blood vessels grow on the surface of the retina, they can bleed into the eye and block vision.