MIT has a lot of catching up to do, according to Brian Mech, vice president of business development at Second Sight. "There are other commercial efforts around the world that aren't as advanced as ours but are more advanced than MITs," Mech told TechNewsWorld.

"There are almost 70 people around the world who have participated in some sort of retinal prosthesis trial," Mech pointed out. "We've had our prostheses in patients for up to six years." Second Sight has the only active prosthesis that has been approved for a trial on humans by the FDA, according to Mech.

Rizzo, who works on the MIT project with Wyatt, told TechNewsWorld that the MIT team used the same epi-retinal approach as Second Sight for 10 years, then switched to the sub-retinal approach because it believed there were huge engineering and biocompatibility advantages.

"The surgery for the sub-retinal approach is more difficult but what we get back in return is worth the added effort," Rizzo explained. "We use a minimally invasive procedure with very little surgery inside the eye, and we believe that will make the product more bio-compatible."

Can They See?

It's not yet clear how effective the prostheses will be. "We're spending a lot of time trying to find out what people see," Second Sight's Mech said. "The performance between patients is variable even though they all have the same device." Some patients see formless blobs while others see objects more clearly.

Second Sight's trial subjects all have retinitis pigmentosa, and the company is not sure why exactly they are responding differently to the implants. "It could be because they have different gene mutations causing the blindness, or the length of time they've been blind, or other factors," Mech said.

However, every subject has been able to see something. "Some subjects can read very large letters, and many have a significant improvement in orientation and mobility; they can detect, locate and recognize objects and detect motion."