How the Eye Works: The Anatomy of The Human Eye

After surveying multiple people on www.changemyeye.com regarding the most important human senses — sight, hearing, taste, smell and touch — people consistently tell us that their eyesight is the mode of perception they value (and fear losing) most. However, most people don't have a good understanding of the anatomy of the eye, how the eye works, and health problems that can affect the eye.

How The Eye Works

In many ways, the human eye works much like a modern day camera:

  1. Light is focused primarily by the cornea — the clear front surface of the eye, which acts like a camera lens.
  2. The iris of the eye functions like the diaphragm of a camera, controlling the amount of light reaching the back of the eye by automatically adjusting the size of the pupil (aperture).
  3. The eye's crystalline lens is located directly behind the pupil and further focuses light. Through a process called accommodation, this lens helps the eye automatically focus on near and approaching objects, like an autofocus camera lens.
  4. Light focused by the cornea and crystalline lens (and limited by the iris and pupil) then reaches the retina — the light-sensitive inner lining of the back of the eye. The retina acts like an electronic image sensor of a digital camera, converting optical images into electronic signals. The optic nerve then transmits these signals to the visual cortex — the part of the brain that controls our sense of sight.
human eye anatomy