Eye movement
Rapid eye movement
Slow eye movement
References
Rapid eye movement
- Eyes move with rapid jerks (saccadic movements) when looking around
- Generates a continuous series of images of different areas
- Eyes fixed on individual areas for 0.2-0.6 seconds before next rapid eye movement
- Surrounding is perceived to be stable when the brain interprets this continuous series of images
- Points of fixation are not evenly distributed but are concentrated around contours and distinctive features
Slow eye movement
- Allow focus on moving object when head is stationary or focus on stationary objects when animal is moving
- Vestibulo-ocular reflex
- Fix image on retina when head is moving
- Ocular muscles move eyeballs simultaneously but in opposite direction to head movements
- Optokinetic reflex
- Stabilise moving image on retina when head is stationary
- Rapid saccade brings eye back to middle position just before slow eye movement reaches outer limit
References
- Sjaastad O.V., Sand O. and Hove K. (2010) Physiology of domestic animals, 2nd edn., Oslo: Scandinavian Veterinary Press.