Humayun: Restoring ‘Vision’ With Sensory Substitution Devices

Created in 1969 by Paul Bach-y-Rita, the very first sensory substitution device consisted of a camera that took pictures and sent signals stimulating the subjects’ back with 400 small, vibrating sensors. Based on that pioneering work, sensory substitution devices today aim to restore “visual” function by activating other sensory modalities such as pressure and sound. Mark Humayun, MD, PhD, provided an overview of sensory substitution devices and their future directions during the Retina Subspecialty Day on Friday.

Visual-to-auditory sensory substitution. The vOICe device offers the experience of live camera views through image-to-sound renderings. As the device scans from left to right, images are converted into sound, associating physical elevation with musical pitch and brightness with loudness. Although promising, such devices have not been widely accepted by patients because of their complex human-computer interface. Subjects must interpret a constant stream of auditory information, which presents a significant cognitive load.

Future directions. With the ever-growing use of smartphones, future visual aids could consist of just a wearable camera and smartphone, providing a compact and powerful way to capture and interpret the surrounding environment. A prototype device based on computer vision interpretation in Dr. Humayun’s lab has shown promise. It provides the user with simple and easy-to-understand cues such as “stairs ahead” and “stop sign to the right.” Dr. Humayun stressed that the involvement of blind users, orientation and mobility specialists, and caregivers will be critical to the design and development of future technologies.—Keng Jin Lee

Financial disclosures. Dr. Humayun: 1Co., Inc.: C,O,P; Alcon Laboratories, Inc.: C,L; Aquesys: C; Clearside: C,O; Eyemedix: C,O,P,S; InnFocus: C,O; IRIDEX: P; oProbe: C,O,P; Reflow: C,O,P; Regenerative Patch Technologies (RPT): C,O,P; REPLENISH: C,O,P; Second Sight Medical Products, Inc.: C,O,P.

Disclosure key. C = Consultant/Advisor; E = Employee; L = Speakers bureau; O = Equity owner; P = Patents/Royalty; S = Grant support.