Advertisement

Latitude Affects Human Eye Size

People living near the Earth’s poles, where days are often short and light often low, have larger eyes and visual cortices than those closer to the equator.

By | July 27, 2011

FLICKR, GAELG

As has been found in some bird and primate species, human eye and visual system sizes vary with the levels of ambient light in a given environment, according to a study published yesterday (July 26) in Biology Letters. Near the Earth’s poles, where average day length and light levels decrease, people have evolved larger orbital volumes, which are known to correspond to larger eyeballs and visual cortex volumes. Visual acuity, however, does not vary among human populations by latitude, suggesting that the changes in ocular size exactly compensate for the lower light levels to maintain an average visual performance.

While a similar relationship between low light levels and visual system size is well documented in birds and non-human primates, which are active at dawn and at night, respectively, this is the first evidence that such variation occurs among human visual systems. Larger eyes, with larger corneas and pupils and more rods and cones, allow for enhanced sensitivity and acuity (e.g., night vision).

Add a Comment

Avatar of: You

You

Processing...
Processing...

Sign In with your LabX Media Group Passport to leave a comment

Not a member? Register Now!

LabX Media Group Passport Logo

Follow The Scientist

icon-facebook icon-linkedin icon-twitter icon-vimeo icon-youtube
Advertisement

Stay Connected with The Scientist

  • icon-facebook The Scientist Magazine
  • icon-facebook The Scientist Careers
  • icon-facebook Neuroscience Research Techniques
  • icon-facebook Genetic Research Techniques
  • icon-facebook Cell Culture Techniques
  • icon-facebook Microbiology and Immunology
  • icon-facebook Cancer Research and Technology
  • icon-facebook Stem Cell and Regenerative Science
Advertisement
Advertisement
The Scientist
The Scientist
Life Technologies