The goal of this clinical investigation is to learn how the brain responds when visual information is converted into patterns of sound or touch in blind and sighted participants. The main questions it aims to answer are:

• Does converting visual information into sound or touch patterns change visual performance in the blind or blindfolded?
• How does the brain adapt to different kinds of sensory information?

Researchers will use brain imaging and simple performance tasks to see how people process and learn from this type of converted sensory input. The investigators will compare how individuals with and without long-term vision loss respond to these signals.

Participants will:

• Learn to use technologies to assist in visual information conversion into sound or touch patterns every day for 5 weeks;
• Visit the brain imaging center 3 times for brain scans and behavioral tests.

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).

No current plan to share data.