A common phenomena among experienced artists is that their sight has changed. They say that now they see things as they really are.
What does that mean?
This in part has to do with the neuropsychology of the brain. Human beings don't see the full spectrum of colors and we also have blind spots in our vision. But normally we are not aware of our shortcomings unless we specifically look for them.
Drawing on the Right Side of the Brain is a book by Betty Edwards which explores one of those blind spots. In particular it explores the habit of the brain to see symbols of objects instead of the full definition of the real object. Because it's easier for the brain to do it's mental arithmetic when it uses approximations of the real world instead of the full high resolution version of it.
You see a symbolic tree instead of the individual characteristics of the tree. This is why children, not only because they lack the fine motor skills, draw their home and family and pet dog at a lower resolution. Children see the big details such as the hair and the skin color and maybe even the length of the legs.
But the ability to look closer and define an eyelash is something that's normally acquired with practice.
Betty Edwards's book is a quintessential beginners book for anyone interested in becoming an artist. By the end of a book you'll be able to draw a fairly realistic portrait of yourself.
You can also keep up with Edwards at her site.