Seeing a solution to partial sight

A partially-sighted

(MIT) poet has developed a small, relatively inexpensive "seeing machine" that can allow people who are blind or visually impaired to access the Internet, view the face of a friend, "previsit" unfamiliar buildings and more.

The work is led by Elizabeth Goldring, a senior fellow at MIT's Center for Advanced Visual Studies. She developed the machine over 10 years, in collaboration with MIT students and professional ophthalmologists. The new device costs about $4,000, much less than the $100,000 machine that inspired it.

Goldring's idea came after an eye examination when technicians looked into her eyes with a diagnostic device known as a scanning laser ophthalmoscope, or SLO. They used it to project a simple image directly onto the retina of one eye, past the haemorrhages within the eye that contributed to her blindness, to determine whether she had any healthy retina left.

She was able to see the image, and asked if they could write the word "sun" and transmit that through the SLO. "And I could see it," she said. "That was the first time in several months that I'd seen a word, and for a poet that's an incredible feeling."

She went on to experiment further with the device, developing a visual language consisting of short words that incorporate graphics and symbols that convey the meaning of text and make it easier to see and read.

As the SLO is bulky and prohibitively expensive, Goldring decided to develop a more practical machine for the broader blind public. She collaborated in her research with Rob Webb, the machine's inventor, eye specialists, designers, an optical physicist and MIT undergraduate and graduate students.

"We essentially made the new machine from scratch," Goldring said. While still allowing the projection of images, video and more onto a person's retina, the team were able to make the desktop device cheaper because it doesn't include the diagnostic feedback of the SLO. The new seeing machine also replaces the laser of the SLO with light-emitting diodes, another source of high-intensity light that is much cheaper. Like the SLO, the seeing machine is designed to be used by one eye.

The team carried out a pilot clinical trial of the seeing machine with visually impaired people recruited from the Beetham Eye Institute. All participants had a visual acuity of 20/70 or less in the better-seeing eye. Subjects had a wide range of cause for vision loss, including diabetic retinopathy, macular degeneration and visual field loss.

Participants used the machine to view 10 examples of Goldring's visual language. A majority interpreted all 10 "word-images" correctly. "They responded really well to the visual language," Goldring said. "One woman told me she would love to see recipes written that way." Less than 10 per cent of the blind read Braille.

They also used the machine to navigate through a virtual environment using a joystick, potentially allowing user to preview unfamiliar buildings they want to visit. The study concluded that all of the participants reported that the machine "may have the potential to assist their mobility in unfamiliar environments."

Goldring and colleagues are now working toward a large-scale clinical trial of a colour version of the seeing machine, where participants can explore a museum gallery containing some of Goldring's art. When a person gets close enough to a piece, the work is explained in Goldring's voice.

This work was supported by NASA and by MIT's School of Architecture and Planning, Center for Advanced Visual Studies, Undergraduate Research Opportunities Program and Council for the Arts.