Board Thread:General Discussion/@comment-10048743-20150715104333/@comment-4651179-20150910201326

The Model 5 Space Armor did have eyeslits, and it's shown to have a plexiglass shield as part of them (like a window) or underneath them. The lenses were only shown when he was in space (the eyeslits showed a typical reflecting glass texture), but in scenes on the Earth or the interior of a space station his eyes could be seen.

Tony's eyes could also be seen through the eyeslits of the Model 10. The eyeslits could also be seen when the "camera" of the panel was inside Iron Man's helmet. Model 10 also had holographic HUD and graphics projected directly onto his retinas, but they only showed additional system data and not what was in the field of view, like in the MCU and later comics.

I can't really say anything about the Model 19 Space Armor.

The Model 45 also had see-through eyeslits. However, pretty much like in the MCU, he relied to see on the suit's HUD, so when he had to shut it down, and leave it in "dumb response" (so it wouldn't be a dead weight), he had to remove his helmet to see.

I'm still not sure when did Tony start relying entirely on the HUD to see the exterior, but I'm sure that trend must've started with the Extremis Armor. I've seen different instances (in the beginning of Vol. 3 and Vol. 4, before he got Extremis) that Tony used the eyeslits to see through, and the HUD only added additional info (like targeting or system status).