According to Pedigree.com, dogs have limited color vision - their eyes have 20 percent of the number of color receptors present in human eyes. Dogs see shades of yellow and blue, but are unable to differentiate between colors ranging from green to red. Dogs perceive red as brownish-gray or black.
As nocturnal hunters in the days before domestication, dogs have much better night vision than humans. Additionally, they are better able to detect motion. While their eyes are more proficient in hunting-related needs, dogs are estimated to have 20 to 40 percent of the visual acuity as humans, rendering what they see as blurry.