Imagine being totally blind and then activating a device that restores your sight, at least in a limited way.

Online videos show exactly that happening. Awed patients laugh and cry seeing their spouses waving, blowing kisses or simply walking by them. One man and his wife shake with laughter that dissolves into a crying bear hug.

“It’s crude, but it’s significant,” he said, holding back tears. “You know? It’ll work.”

The visual prosthetic is made by Sylmar’s Second Sight Medical Products Inc., which recently sold stock in an initial public offering. Some patients describe their new functional sight as looking like pulsing or flashing lights that illuminate contours. Now they can reach out for a salt shaker, tell where the sidewalk meets the grass or see other diners surrounding them at a restaurant.

While even this rudimentary vision might seem like magic, it comes with a very real price tag: $144,000.

It also comes with very real limitations. The implantable prosthetic system, the Argus II, is only approved in the United States for people who lost their eyesight because of retinitis pigmentosa, a hereditary eye disease that affects about 100,000 stateside. In addition, the device can only treat about a quarter of those patients. The system is approved for broader use in Europe and has closer to 1 million potential takers there.

What’s more, getting Medicare and private insurers to cover the cost can be a slow process, as with many new medical devices.

Vision quest

Outwardly, the Argus II looks like a pair of sporty shades with a tiny video camera embedded in the bridge. The camera sends footage to a Walkman-size wearable computer. The data is processed, sent through a cable back to the glasses and transmitted wirelessly to an antenna on a tiny prosthetic implanted in and around the eye. Electrodes in the implant emit small pulses of electricity that bypass the eye’s damaged cells and stimulate the good ones, sending the visual information along the optic nerve to the brain. The process creates the perception of light patterns that patients learn to interpret.

The Argus II, the second iteration of the bionic eye, started clinical trials in 2006, eight years after the company was co-founded by prolific biotech entrepreneur Alfred E. Mann. It received marketing approval in Europe in 2011 and the blessing of the Food and Drug Administration two years later. The process was expedited because the device treats what’s considered an orphan or rare disease.