The eye and how it works: understanding how we see

Each step must function perfectly for our perception of the world to be accurate and stable.

The eye can be compared to a high-performance camera equipped with advanced features:

• Autofocus, to adjust sharpness according to the distance of objects

• Dynamic object tracking, so you never lose sight of what you're watching

• Adaptation to light, to see in the dark or in bright sunlight

• Automatic cleaning, thanks to blinking and tears

And all of this is connected to an information processing system (the brain) whose complexity exceeds that of any current computer.

The cornea is the gateway for light into the eye. It plays an essential role in focusing images on the retina.
To fulfill this function, the cornea must remain clean and transparent, protected by:

• blinking of the eyelids,

• and tear secretion, which cleans and moisturizes its surface.

The lens allows the eye to focus on objects both near and far.
To do this, it changes shape thanks to the tendons that connect it to the muscles of the eye:

• Zoom in to see up close

• Flattens out to see from afar

This ability to adjust is called accommodation, and it is essential for clear vision at all distances.

The pupil, located in the center of the iris, functions like the diaphragm of a camera: it regulates the amount of light entering the eye.

Two groups of muscles control the pupil:

• Radial fibers, which dilate the pupil

• Circular fibers, which shrink it

Thus, the pupil automatically adapts to changes in brightness to protect the eye and improve vision.

The retina is a thin layer of nerve tissue (≈ 0.25 mm) at the back of the eye, comparable to photographic film. It consists of three main layers:

Photoreceptors: light-sensitive cells (rods and cones)

Intermediate cells, which process light information

Ganglion cells, which transmit the electrical signal to the brain via the optic nerve

Photoreceptors convert light energy into electrical signals, which the brain then interprets as a clear and precise image.

Vision is the result of perfect collaboration between the different structures of the eye and the brain.

• The cornea and lens focus light.

• The pupil regulates brightness.

• The retina captures light and transmits information.

• The brain interprets the signal to create the vision we perceive.

It is thanks to this complexity that the human eye remains, even today, unmatched by technology.

At Optique Moitzheim, our opticians explain how the eye works, advise you on your glasses and corrective lenses, and help you choose the best protection for your eyes.

Make an appointment in-store and receive personalized advice.