Here is an image of a group of statuettes said to be close to 5000 years old. The subscript says they're adoring the gods. I suggest that's a misapprehension. I'll explain why after you've looked at the image:

Two beings, apparently one male and one female, have very large round eye sockets. Inserted into those sockets are white eyeballs and huge blue discs far larger than any human irises. Neither of them has normal human eyelids. In the case of the male only, there is a central black blob, perhaps the equivalent of a central pupil. The female with blue disks in her eye sockets has no pupils. What we see may represent the actual eyes of these two beings, or their 'shades' ( like sunglasses) or contact lenses to keep out excess light. We are reminded of the references in Biblical texts to humans not being able to live if they saw Immortals, the ancient gods. Perhaps there was something about their eyes that made them not just distinctive, but with their gaze harmful to humans. The lips of these two beings are shown as thin, narrow and rectangular. The resulting effect of their overall physiognomy is to create two pitiless-looking creatures.

The apparent female in the front has human-shaped eyes, but incorporating the bright blue of the larger and taller figures behind and to her right. She has human-like white eyeballs, with blue irises and black pupils. The shape of her eye sockets is human. She even has a human upturned mouth giving the effect of a slight smile. The pattern of creases in her forehead give the impression she has just begun to pose for a photographer. If the two beings behind her right side are Immortals, which seems possible, then she may be a half-Immortal, that is, in her case, possibly the product of her Immortal father's mating with a mortal woman.

The other apparent male in the background does not have coloured implants in his eye sockets, which are shaped more into human form. He has normal shaped eyelids. He has human style lips, but they are compressed and down-turned, creating a somewhat sour and stern disposition. He gives the impression of being an important human individual. He may be a related king, not of complete Immortal nor even half-Immortal stock, but of a subsequent generation with Immortal blood in him.

This group is from the Sumerians, in Mesopotamia. It may be our best chance to see for ourselves just what the Immortals looked like. But that still leaves at least three possibilities. This may be how they looked to humans who saw them, or, this may be how they presented themselves to humans, changing their original actual form to be more acceptable to humans. In that case they could not apparently assume entirely human eyes and still see in earth's environment. The third possibility is that the Immortals never did change their form, but by some exertion of power over human senses caused humans to think that's what they saw. I suspect this latter suggestion is unlikely because it's the different eye formation that inadvertently reveals who they really are. The eyes of these beings had a profound effect on humans, and that's what we'll look at in the next chapter.