Geordi Laforge was the Chief Engineer aboard the Enterprise-D and later on the Enterprise-E, although he began the TNG series as a member of the bridge crew. He started out as a Lieutenant and eventually reached the rank of Commander.
Geordi was born completely blind. His eyes appear to be solid white with no sign of pupil, iris or lens. To compensate, he wears a VISOR which actually allows him to see a far greater range of EM-frequencies than normal eyes would.
Sometime after the regular series, he had the device replaced with more natural-looking artificial eyes, as seen in Star Trek: First Contact.
The metaphasic radiation in Star Trek: Insurrection appears to have caused real eyes to grow, supposedly eliminating the need for artificial implants altogether. There is no evidence either way in Star Trek: Nemesis, although his eyes in the film are not the same color they were in Insurrection or when Riker restored his sight in "Hide and Q" (brown). The color seen in Nemesis does seem to match that seen when we see him in the future in "All Good Things" or the Voyager episode "Timeless" (blue-grey).
In the non-canon novel, Star Trek: Destiny: Gods of Night, La Forge is promoted to the rank of commander.