Healthy eyes with normal vision do not need visual aids.

The Eye

How it works

The Eye

A sensitive and complex sensory organ

The eye is one of the most important, sensitive and complex sensory organs in the human body. It allows you to gather information about the world and experience its colors and beauty. In many ways, the human eye works much like a camera: Sight is the result of the eye focusing incoming light onto the back of the eye. From there, millions of receptors send the information to the optic nerve, which transfers information to the brain. This is where a single, three-dimensional image is constructed. In order to create a perfectly focused image, all parts of the eye need to work together perfectly.

If your vision is impaired due to a refractive error or the natural aging process, this might have a direct impact on your quality of life and can be very frustrating. The most common vision defect is nearsightedness (myopia). Learn more about this and other vision conditions on the following pages.

The Anatomy of the Eye

How vision works

The human eye is a complex organ and visual system, made up of three layers and enclosing various anatomical structures. This section explains how different parts of the eye work together to provide vision.

How vision works in detail


Living with nearsightedness

For nearsighted eyes, objects in the distance appear blurry, but objects up close are sharply focused. This condition can occur if the cornea is too steep and incoming light is not accurately focused onto the back of the eye.

About myopia and options to correct it



Living with farsightedness

For farsighted eyes, objects up close appear blurry, but objects in the distance are sharply focused. This condition can occur if the cornea is too flat for the length of the eye.

About hyperopia and options to correct it


Close and distant objects appear blurred, skewed or distorted

Astigmatism is caused by an unevenly shaped cornea or natural lens. Vision is blurred or distorted to some degree at all distances.

About astigmatism and options to correct it



Age-related farsightedness

Presbyopia is the age-related, natural regression of vision. It occurs when the natural lens loses its ability to focus on near objects.

About presbyopia and options to correct it