In Mary Shelley's Frankenstein, there is a great deal of vivid imagery that helps share Victor's sense of horror when looking at the creature he has brought to life.

...by the glimmer of the half-extinguished light, I saw the dull yellow eye of the creature open...

Victor then describes how it takes its first breath. In an instant—a moment of epiphany—the pains Victor Frankenstein had taken to construct a creature of beauty are illuminated before him to see, instead, the truth of what he has done: he has made a horrifying mistake, a crime against God and nature—a monstrous looking being.

I had selected his features as beautiful. Beautiful!—Great God! His yellow skin scarcely covered the work of muscles and arteries beneath; his hair was of a lustrous black, and flowing; his teeth of pearly whiteness; but these luxuriances only formed a more horrid contrast to his watery eyes, that seemed almost of the same colour as the dun-white sockets in which they were set, his shrivelled complexion and straight black lips.

Victor flees from his workroom and falls asleep only to waken to the creature reaching toward him, grinning. Once again Victor runs away.

He writes:

I had gazed on him while unfinished; he was ugly then; but when those muscles and joints were rendered capable of motion, it became a thing such as even Dante could not have conceived.

The potent and precise imagery Shelley adopts in describing the monster's appearance, along with Victor's reactions, brings to the reader's mind a sense of horror similar to the creator's. Victor Frankenstein's responses are all based simply upon appearance, which will be one of the creature's criticisms not only of Victor, but also of society in general.

It seems that the creature's looks horrify Victor the most. I can only surmise, but it is perhaps the eyes that would be the most horrific of the things that so chill Victor's heart because as people we often look to a person's eyes to glimpse one's thoughts, intent, emotions, and soul. In this case, it may well have seemed to Victor that the creature's eyes, so bizarre in their color and presentation, would have been most haunting and terrifying.

On Chapter 5 of Mary Shelley’s Frankenstein we witness the final step of the creation of the creature:  The moment when the creature comes to life.

It is very significant that Victor Frankenstein, who once wished with all his heart to create life, is now haunted by what he sees in front of him. Nothing is like he expected. What once was a fascinating curiosity has transformed into the nightmare of having created a monstrous creature that was somehow brought to life. What is worse, the creature seems to have the mannerisms and emotions of a regular human being. Yet, these very characteristics are what make its existence more morbid.

In Victor’s own words:

His limbs were in proportion, and I had selected his features as beautiful. Beautiful! -- Great God! His yellow skin scarcely covered the work of muscles and arteries beneath; his hair was of a lustrous black, and flowing; his teeth of a pearly whiteness; but these luxuriances only formed a more horrid contrast with his watery eyes, that seemed almost of the same color as the dun white sockets in which they were set, his shriveled complexion and straight black lips.

Victor describes the creature with disgust and fear. As readers, we can perceive a combination of amazement and horror. Victor particularly seemed to detest the creature’s eyes. After all, those very eyes looked straight at Victor, at one point, with the same innocence and need with which children look at their parents.