The human eye has two lenses that work together to focus light onto the retina. The outer focusing lens is called the cornea. The inner focusing lens is called the crystalline lens. Light rays pass first through the cornea and then through the crystalline lens.
The cornea and crystalline lens focus incoming light by bending all the light rays to meet at a single point on the retina. From the retina, these light rays are sent as electrical pulses to the brain where our mind “sees” a picture of what’s in front of us.
OCULAR ANATOMY
Vision changes with age
The aging process affects the clarity and quality of vision, which may impact your ability to read or drive at night. Two primary causes of vision loss with age are cataracts and presbyopia.
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The natural crystalline lens of the eye is made mostly of water and protein. Sometimes in a person’s 60s, 70s, or 80s, some of the protein will clump together, causing the eye’s natural lens to become discolored and clouded. This clouding of the natural lens is called a cataract.
When this occurs, light rays passing through the eye become scattered and unfocused. The result is that all objects, whether near or far, become blurry. If left untreated, cataracts can lead to blindness, although this is very uncommon in the United States. To help you better understand cataracts, watch an animation of the development of a cataract.
CATARACTS
The only treatment for a cataract is removal of the affected natural lens of the eye and implantation of a lens implant, or intraocular lens (IOL). This restores the eye’s ability to have light pass unobstructed through to the retina. Over 15 million IOL procedures are performed worldwide each year.
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As we age, the natural crystalline lens in our eye becomes less flexible. This lack of flexibility compromises the eye's ability to switch from one focal point (objects at a distance — driving) to another focal point (objects that are close — reading). This is called presbyopia.
The practical effect of this loss of flexibility in the natural lens of the eye is that we lose our ability to read or see close objects without reading glasses or bifocals. To help you better understand presbyopia, watch an animation of this process.
PRESBYOPIA
Today, for people who have cataracts with or without presbyopia, there is a procedure to remove the affected natural lens of the eye and replace it with an advanced TECNIS Multifocal Lens. This implantable lens provides focused vision in all depths of field — near, intermediate, and far — in all lighting conditions.
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This information is for educational purposes only. Talk to your eye doctor about any symptoms you may be experiencing and find out if the TECNIS Multifocal Lens is appropriate for you.