Answer to Question #252883 in Genetics for lola

Question

Roger is legally blind. His vision impairment is a complication of diabetes mellitus. Can you describe what structural changes in Roger’s eyes have caused his blindness? As you were helping him cross the street, a fellow pedestrian suddenly stumbled into your path. Without any signal from you, Roger jumped back to avoid hitting the other person. If Roger is blind, how could he have reacted this way?

Answer 1

Roger's condition is known as diabetic retinopathy. In this disorder, diabetes causes small hemorrhages in retinal blood vessels that disrupt the oxygen supply to the photoreceptors. Due to the damage in the blood vessel that disrupted the oxygen supply new abnormal vessels have blocked Roger’s vision. These abnormal vessels also could affect the retina by allowing it to detach, which is the reason why Roger’s is now legally blind.

Even though, Roger is not able to see while crossing the street since he is blind. Roger has other senses that have become sharper due to his condition. His hearing sense allowed him to hear that another person was close enough for him to bump or hit the person. This is why Roger was able to jump back without seeing the other person. Most blind people have an amazing ability to touch, smell or hear with a high degree of acuity.