Rudolph's eyes are a bright, vibrant red, which is why they are so noticeable and famous. The red color comes from a condition called "albinism," which means Rudolph lacks the pigment melanin that gives other reindeer their brown and black colors. Without melanin, Rudolph's eyes are sensitive to bright lights, which is why they appear so bright and shiny in the sunlight and why he can see better in the dark.