Rod and Cone Mediated Function in Retinal Disease

Background: Retinal diseases cause the loss of rod and cone photoreceptors. Symptoms include vision loss and night blindness. Researchers want to learn about rod and cone function in healthy people and people with retinal disease. They want to know if how well a person sees in the dark can test the severity of retinal disease. Objectives: To find out if how well a person sees in the dark can test the severity of retinal disease. To find out if this can help detect retinal disease and track its changes. Eligibility: People ages 5 and older with: Retinal disease OR 20/20 vision or better with or without correction in at least one eye Design: Participants will be screened with medical and eye history and eye exam. Those with retinal disease will also have: Eye imaging: Drops dilate the eye and pictures are taken of it. Visual field testing: Participants look into a bowl and press a button when they see light. Electroretinogram (ERG): An electrode is taped to the forehead. Participants sit in the dark with their eyes patched for 30 minutes. Then they get numbing drops and contact lenses. Participants watch lights while retina signals are recorded. Visit 1 will be 3-8 hours. Participants will have up to 6 more visits over 6-12 months. Visits include: Eye exam and imaging Time course of dark adaptation: Participants view a background light for 5 minutes then push a button when they see colored light. Dark adapted sensitivity: Participants sit in the dark for 45 minutes. They push a button when they see colored light. For participants with retinal disease, ERG and visual field testing ...

* INCLUSION CRITERIA: * Participant must be five years of age or older. * Participant (or legal guardian) must understand and sign the protocol s informed consent document. * Participant must be able to cooperate with the testing required for this study. For Participants with retinal disease only: * Participant must have retinal disease, defined as evidence of loss of retinal dysfunction and/or degeneration as established by standard clinical methods including perimetry, ERG and imaging. * Participant must have a measurable visual acuity. For Healthy Volunteers only: -Participant must have visual acuity of 20/20 or better, with or without correction (e.g., glasses or contact lens) in at least one eye. EXCLUSION CRITERIA: -Participant with changes in pre-retinal media sufficient to obscure a view of the retina.