Eye Anatomy

Eye Anatomy Laser vision correction maybe right for you, however, it is important to understand how your eye functions. The primary purpose of the visual system is to focus light. Contact lenses or glasses may be needed to focus rays of light properly.

The best way to understand function of the eye is to compare it to a camera. Light enters the eye through the cornea often referred to as the “window of the eye.” The light travels through the pupil and then through the lens. The lens acts by fine-tuning the focus of light onto the retina. The retina turns the light energy into electrical impulses that travel from the eye to the brain where the image is interpreted.

Below are basic descriptions of the various parts of the eye, which will help you understand the process of vision and how refractive disorders may be corrected.

CORNEA: Your eye’s cornea is the most anterior surface of the eye and provides most of the focusing power. The cornea acts as the eye's outermost lens. It functions like a window that controls and focuses the entry of light into the eye. Small changes in the cornea can have a large effect on how the eye focuses light.

PUPIL: The pupil is the black spot or hole in the center of the iris. It appears black because most of the light entering the pupil is absorbed by the tissues inside the eye. The pupil acts to regulate the amount of light that enters the eye. In the bright sunlight, it becomes smaller to let in less light. In a dark environment, the pupil expands to allow more light to reach the retina.

IRIS: The iris is the colored part of the eye. The muscles of the iris act to control the size of the pupil. The iris color comes from microscopic pigment cells called melanin. The color, texture, and patterns of each person's iris are as unique as a fingerprint.

LENS: In young people, the lens changes shape to adjust for close or distance vision. This is called accommodation. Your eye lens is a normally clear structure located behind the pupil. It acts to fine-tune focusing. By changing shape, the lens allows focusing at far and near. With age, the lens gradually hardens, diminishing the ability to accommodate. This is called presbyopia. Most people notice this in their early 40’s. In people over 60, the lens may become cloudy and interfere with vision. This is called a cataract.

RETINA: The retina is a multi-layered sensory tissue that lines the back of the eye. It contains millions of photoreceptors that capture light rays and convert them into electrical impulses. These impulses travel along the optic nerve to the brain where they are turned into images. It is very similar to film in a camera in that it functions to capture and transmit images to the brain.

OPTIC NERVE: The optic nerve connects to the back of the eye near the macula. The optic nerve carries the images from the retina to the brain. When examining the back of the eye, a portion of the optic nerve called the optic disc can be seen.

SCLERA: The sclera is the support layer of the eye. The sclera is commonly known as "the white of the eye." It is the tough, opaque tissue that serves as the eye's protective outer coat. Six tiny muscles connect to it around the eye and control the eye's movements.

VITREOUS: The vitreous is a thick, transparent substance that fills the center of the eye. The vitreous fills the space between the lens and the retina. It is composed mainly of water and comprises about 2/3 of the eye's volume, giving it form and shape. Opacities in the vitreous are seen as floaters.

We want our patients to have the knowledge to make informed decisions about their eye care needs. Please call 1.800.527.3745 to schedule your appointment today.