You know the saying, the eyes are the windows of the soul? Well, I'm not sure exactly how I feel about that. However, the eyes are great tools and indicators in fiction writing. Telling readers that a character is 'looking' at something or someone is fine, but showing them how a character sees the object or the person is much more powerful.
Let's say your character looks at someone across the room. That statement tells the reader absolutely nothing about how the character feels when they see that person. Showing the reader how the character feels requires a more extensive vocabulary. Let's say your character gawks at someone across the room. This tells us a little bit more. Your character is most likely attracted to the person. Word choice can be taken even farther here. A character who is typically shy might gawk at someone they are attracted to, while a more self-assured person may ogle. Is your character an awkward teenage boy gaping at a young woman? Is your character a creep? In that case, they might be leering at the person across the room.