Yeah, my understanding was that they hooked up infrared sensors to optical nerve. The ability that seemed interesting was that they fairly quickly were able to map the new sensory input and use the information and could do so with or without light in the normal visual range.
In some sense this is similar to having a seeing impaired person with some distance locating device that gives signals either through touch or hearing.
Simple example here.
Rats Detect Light Without Sight 
Linear Mode
