Zach Van Sickle Alyssa Kaeser Human Vision Zach Van Sickle Alyssa Kaeser

Color Blindness The eye detects three colors: red, blue, and green. All other colors are a combination of varying degrees of these three colors. Color blindness is a vision deficiency in which the perception of colors is different from one person than that of normal vision. Color blindness varies in intensity, the most severe cases being those of complete color blindness. Color blindness is due to an inactive photopigments caused by defective genes. There are three types of colorblindness, due to which gene is affected. https://nei.nih.gov/health/color_blindness/facts_about

Color Blindness There is no cure for color blindness. However, people with red-green color blindness may be able to use a special set of lenses to help them perceive colors more accurately. Visual aids have also been developed to help people cope with color blindness. There are iPhone and iPad apps, for example, that help people with color blindness differentiate between colors https://www.cnet.com/news/dankam-smartphone-app-aids-the-color-blind/

Cataracts A cataract is a clouding of the normally clear lens of your eye. Clouded vision caused by cataracts can make it more difficult to read, drive a car (especially at night) or see the expression on a friend's face. Cataracts are caused in several ways including: age related, congenital, secondary, and trauma. http://www.mayoclinic.org/diseases-conditions/cataracts/home/ovc-20215123

Cataracts Symptoms vision that’s cloudy, blurry, foggy, or filmy Nearsightedness (in older people) Problems driving at night Problems with glare during the day Double vision in the affected eye Trouble with eyeglasses or contact lenses not working well Changes in the way you see color http://www.webmd.com/eye-health/cataracts/what-are-cataracts#1

Cataracts In mild cases, cataracts can be treated with glasses or contacts lenses. In severe cases, cataract surgery may be necessary to correct vision. Cataract surgery consists of removal of the outer lens and a replacement with an artificial lens. http://www.webmd.com/eye-health/cataracts/what-are-cataracts#1

Rods Rods: Receptors in our eyes that are highly perceive to light and dark These perceive motion the most and are much more numerous than cone receptors. These are most responsible for our night vision because they perceive light well. Rods are more numerous in our periphery, which is why we can see objects in dim light better when looking beside them instead of directly at them. http://faculty.washington.edu/chudler/retina.html

Cones Cones: Receptors in our eyes responsible for the perception of color These are less numerous in the eye than rods and only work well in bright light. This is why we don’t see color in dim light; however, cone receptors allow us to detect finer details than rods allow. http://faculty.washington.edu/chudler/retina.html

Binocular Vision Binocular Vision- Vision wherein both eyes aim simultaneously at the same visual target STEREOPSIS: (or stereoscopic vision) vision wherein two separate images from two eyes are successfully combined into one image in the brain. http://www.children-special-needs.org/questions.html

How it Works Both eyes aimed at the same target perceive two similar(but not identical) images The brain sorts out the two different images and combines them into one. Because the combined images are different, the resulting image has an added depth dimension http://www.children-special-needs.org/questions.html

This is how the brain takes the two different images and combines them into one three- dimensional image http://www.children-special-needs.org/questions.html

Common Tasks that Require Binocular Vision Throwing, catching or hitting a ball Driving and parking a car Planning and building a three-dimensional object Threading a needle and sewing Reaching out to shake someone's hand Pouring into a container Stepping off a curb or step http://www.children-special-needs.org/questions.html

Review Questions T/F: The eye detects red, blue, and purple as it’s base colors. T/F: There are visual aids to correct color blindness T/F: Cataracts is an inflammation of the eye T/F: A symptom of cataracts is a glare during the day or while driving at night. T/F: There is no treatment or aid for cataracts.

Review Questions 6. What in our eyes is responsible for perceiving light and dark? 7. What in our eyes is responsible for the detection of color? 8. T/F Humans have stereoscopic vision. 9. What organ in our body merges images from each eye into a three-dimensional image? 10. T/F We can have proper depth perception with one eye closed.

Works Cited Facts About Color Blindness. (2015, February). Retrieved February 23, 2017, from https://nei.nih.gov/health/color_blindness/facts_about Kozarsky, A., MD. (2016, September 24). What Are Cataracts? Retrieved February 24, 2017, from http://www.webmd.com/eye-health/cataracts/what-are-cataracts#1 Cooper, R. (n.d.). What is Binocular Vision? Retrieved February 24, 2017, from http://www.children-special-needs.org/questions.html Chudler/University of Washington, E. H. (n.d.). Neuroscience For Kids. Retrieved February 24, 2017, from http://faculty.washington.edu/chudler/retina.html