How Vision Works

Before we attempt to go deep into improving our eyesight the natural way, we need to first understand how our vision is achieved, i.e. how we are able to see what we are seeing.

You see, visual perception begins as soon as the eye focuses light onto the retina, where it is absorbed by a layer of photoreceptor cells. These cells convert light into electrochemical signals, and are divided into two types, rods and cones, named for their shape.

Rod cells are responsible for our night vision, and respond well to dim light.

Rods are found mostly in the peripheral regions of the retina, so most people will find that they can see better at night if they focus their gaze just off to the side of whatever they are observing.

Cone cells are concentrated in a central region of the retina called the fovea; they are responsible for high acuity tasks like reading, and also for color vision. Cones can be subcategorized into three types, depending on how they respond to red, green, and blue light. In combination, these three cone types enable us to perceive color.

Signals from the photoreceptor cells pass through a network of interneurons in the second layer of the retina to ganglion cells in the third layer. The neurons in these two retinal layers exhibit complex receptive fields that enable them to detect contrast changes within an image; these changes might indicate edges or shadows. Ganglion cells gather this information along with other information about color, and send their output into the brain through the optic nerve.