How the eye works:
Clear vision occurs when light rays enter the eye and are focused by the cornea and lens directly on the retina (Emmetropia).
Myopia (Nearsightedness) occurs when light is focused in front of the retina causing blurry distance vision.
Hyperopia (Farsightedness) occurs when light is focused behind the retina causing blurry near and sometimes distance vision also.
Astigmatism occurs when the cornea is curved more in one direction than another causing light rays to focus at 2 points. This results in distorted or blurry vision.
Presbyopia is a condition in which there is reduced reading vision first noticed around age 40.
Parts of the Eye:
Cornea: the clear front window of the eye. The cornea transmits and focuses light into the eye.
Iris: the colored part of the eye. The iris helps regulate the amount of light that enters the eye.
Pupil: the dark center in the middle of the iris. The pupil determines how much light is let into the eye.
Lens: the transparent structure inside the eye that focuses light rays onto the retina. When it becomes cloudy, it is called a cataract.
Retina: the nerve layer that lines the back of the eye. The retina senses light and creates impulses that are sent through the optic nerve to the brain.
Macula: a small central area in the retina that allows us to see fine details clearly.
Optic Nerve: the nerve that connects the eye to the brain. The optic nerve carries the impulses formed by the retina to the brain, which interprets them as images.
Vitreous: the clear, jelly-like substance that fills the middle of the eye.
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Center For Sight offers this Web site about eye care services for informational purposes only. The content contained here should not be perceived as formal medical advice, nor does the understanding constitute a formal medical relationship with the Center For Sight.
