[more nerd] and even if he did have the needed ocular implants, that's NOT how his visor works. It registers energy patterns, radiation, and various elements in the environment. He doesn't actually "see" with it. Not only is the view through Geordi's visor shown to us in the series - there's also an episode where Q gives him real sight briefly and he can finally see everyone and is moved by it. [/more nerd]
http://4.bp.blogspot.com/-m1MgHdwheRo/T9DUQHiM9VI/AAAAAAAAAaE/h4yXEgc3j44/s1600/111.jpg
In Japan this time, the Gate Tower in Osaka.
...on second read, positive current flow allows it to be transparent; it turns opaque when the flow is cut. Neat!