Sight or vision is the capability of the eyes to receive visible light through the retina of each eye to where our nerve receptors send messages to our brain that we translate as colors, hues, and brightness. We have two main receptors in our eyes called cones and rods. Rods distinguish light not color. Cones are responsible for all the colors we see, but are sensitive to dim light, for example it’s difficult to make out colors in poorly lit situations yet you can see the shape of the object. The inability to see is called blindness. Multiple things cause blindness: damage to the eyeball, especially the retina, the optic nerve and strokes. Temporary blindness can be caused by medications. There are two classifications of blindness: Congenital Blindness where you’re born blind or became blind before you were five and adventitiously blind are for people who went blind later in life, so after 5.
According to a study done by Hartford University where they analyzed 392 dreams of 15 blind people they didn’t have any visual dreams with the congenitally blind. That’s because our dreams are perceived by real world experiences, anxieties and desires and people who have never experienced light or just don’t remember won’t dream visually. The longer you’ve had sight the longer you’ll see while dreaming. Does this mean the visually impaired don’t dream? No. They have dreams called sensory compensated dreams. They dream of their life as they live life, but in a dream state just like us. They feel, smell, hear and taste whatever is in their dream. Because they lack the ability to see, the brain emphasizes these senses. In one study of dreams, 60% of blind people reported dreaming about transport (compared to 28% of sighted people) which is understandably a big cause of anxiety for blind people because of the danger it presents. Research has also shown that people who don’t dream visually show little or no rapid eye movement during the REM phase of sleep
Bibliography: Turner, Rebecca. "What Do Blind People Dream About?" What Do Blind People Dream About? N.p., n.d. Web. 24 Oct. 2013. Hurovitz, C., Dunn, S., Domhoff, G. W., & Fiss, H. (1999). The dreams of blind men and women: A replication and extension of previous findings. Dreaming, 9, 183-193. "Human Brain: Can Someone Born Blind Dream?" Quora. N.p., n.d. Web. 28 Oct. 2013.