No, no eyes!

leading from

Creating the Alien

Giger's Alien head at the Giger museum

The creature from Giger's painting Necronom IV had slanted bulbous eyes perhaps inspired by motorcyclist goggles and it became too much like a Hells Angel so they were removed and with this creatures bulbous head from the front it looked a bit like depictions of reports of extra-terrestrials from Zeta II Reticuli known as The Greys. Giger became fascinated with the idea of the creature being eyeless. They wanted him to include lamps behind the eyes but he decided "No, no eyes". They said to him to "Please try it" but it didn't work.

quote source

1. H.R.Giger: The big problem was with the [full-grown] monster. In the first design, head had big black eyes, but somebody said he looked too much like a Hell's Angel, all in black with the black goggles. Then I thought it would be even more frightening if there were no eyes. So when the camera comes close, you see only the holes of the skull. Now that's really frightening. Because even without eyes he always knows exactly where his victims are, and he attacks directly. (Cinescape vo.3 no.9, p22)
2. H.R.Giger: All these beasts are blind. I think it is very frightening to have beasts with no eyes. At first they wanted it to have eyes with lamps behind them. Other people always wanted that  but I decided No, no eyes. They said please try it but it didn't work. I think the final version looks quite believable. (Film Monsters # 158, p31)
3. H.R.Giger: And all these beasts are blind. I think it's very frightening to have blind beasts. At first they wanted eyes with lamps behind them. But I said no, no eyes. They said please, but it didn't work. (Warren Present Alien Collectors Edition, p35)