Sensory Substitution and Brain Plasticity Following Vision Loss

Inclusion Criteria: 1. 8-85 years old for blind individuals; or 18-85 years old for sighted controls. 2. (a) Blind due to ocular impairment (documented visual acuity of light perception or worse) in both eyes, or (b) sighted healthy adult controls with corrected visual acuity of 20/40 or better and with no known vision disorders. 3. Able to hear the Informed Consent Form being read out to him or her, to understand it, and sign the Informed Consent Form. 4. Able to undergo functional neuroimaging tests. 5. Able to walk and stand independently. 6. Able to understand and remember the training protocols involved in the research study. 7. Willing and able to use the provided sensory substitution system to solve simple visual tasks. 8. Willing and able to complete simple tactile or auditory tasks. 9. Able to communicate by telephone and/or computer with research staff. Exclusion Criteria: 1. Prior use with the sensory substitution device under investigation. This applies to both the auditory and tactile stimulators. 2. Presence of any foreign metal in the body, except for dental fillings (will need to be pre-screened by a radiologist prior to signing the informed consent and enrollment). 3. Pregnant or breastfeeding by self-report or urine test. 4. Is a prisoner or has any required movements legally restricted. 5. Unwilling or unable to adhere to all study requirements, including completion of the training period and any evaluation tests. 6. Implanted electrical medical devices such as pacemakers. 7. Claustrophobia that would prevent functional neuroimaging. 8. Obesity preventing placement in the MRI scanner. 9. No known neurological disorders or any medical condition that can possibly lead to emergency medical care (e.g., history of seizures, family history of epilepsy, stroke, severe headaches, use of medication for neurological or psychiatric conditions). 10. Documented or suspected brain damage resulting in significant cognitive or sensory impairment (e.g., traumatic brain injury).