binocular vision

Question 1

advantage of binocular vision

Answer 1

combines information from both eyes
increase field of view
compensate for physiological blind spot
stereopsis

Question 2

monocular vision

Answer 2

only info from single eye used by brain

Question 3

simultaneous perception

Answer 3

images from both eyes seen at same time

Question 4

sensory fusion

Answer 4

images from each eye fuse into single percept

Question 5

steropsis

Answer 5

ability to use subtle differences between each image to extract information about depth

Question 6

levels of binocular vision

Answer 6

monocular
simultaneous perception
sensory fusion
stereopsis

Question 7

testing stereopsis

Answer 7

measured in arc seconds
TNO test
lang test
crosby test
titmus test

Question 8

cover test: for heterophoria and heterotropia

Question 9

in order to perceive a single fused image from two eyes at the same time we need

Answer 9

motor fusion - two eyes must be physically aligned and pointing almost in the same direction

sensory fusion - final alignment done by brain and corrects for minor alignment

Question 10

amblyopia (lazy eye)
and treatment

Answer 10

• young brain is good at adapting to double vision
• turns off image from eye
• one eye doesn’t work as well as other
• signal is ignored by brain

glasses and patching stronger eye to make weaker eye work harder

Question 11

convergence
and testing and blur

Answer 11

ability to focus on near object with both eyes

• important to distinguish between doubling and blur
• people with hyperopia or presbyopia can experience blur before doubling so makes test difficult

Question 12

presbyopia

Answer 12

• lens loses flexibility throughout life
• reduced ability to accommodate (focus and near vision)
• symptom is blur
• reading glasses