Reflex eye movements and their misconceptions

Question 1

Functions of eye movements

Answer 1

1. Stabilizing images : preventing retinal image ‘jiggle’ to maintain clear vision
2. Focusing images : Positioning objects of interest onto the retinas fovea for detailed vision

• Moving retinal images disrupt clarity making it vital to stabilise them

Question 2

Purpose of the Vestibulo- ocular reflex (VOR)

Answer 2

• Keeps eyes fixated on an object as the head moves
  eyes counter-rotate to maintain the same direction of gaze

Question 3

characteristics of VOR

Answer 3

• operates in all 3 dimensions
• does not involved the spinal cord, entirely mediated by the brain and head circuits
• complemented by reflexes that stabilize the head reducing VOR workload

Question 4

Types of eye movements

Answer 4

Rapid movements - saccadic eye movements - quick shifts in gaze from one position to another

Slow movements: Gradual movements like those generated by the VOR

Question 5

Saccadic movements

Answer 5

enable rapid changes in focus between objects
include stationary periods between movements called fixations

Question 6

conjugate movements

Answer 6

Both eyes move in the same direction and angle

Question 7

disconjugate movements

Answer 7

eyes move in opposite directions