A cataract is a clouding or loss of clarity of the natural lens of the eye. Cataracts are increasingly common with aging and can occur in one or both eyes. Cataracts do not spread from one eye to the other.
What causes cataracts?
Cataracts can occur with age, trauma, use of certain medications (notably steroids) and can be associated with diseases (e.g., diabetes). Cataract progression may be exacerbated by social habits (e.g., smoking and alcohol use). Extensive sun-exposure has been linked with cataract formation. Importantly, what is an insignificant cataract in one person's life may be more impacting to another.
How can cataracts affect your life?
Clouding of vision: Cataracts typically start in a small part of the lens and may be noticeable to the ophthalmologist but not the patient. The vision may worsen so gradually that the patient adjusts to it without realizing. As the cataract advances, the vision may get duller or darker.
Change in color perception: As cataracts develop the lens change from clear to yellow and eventually to brown. This change does not necessarily reduce acuity (vision) but color-sensitive people can misinterpret or incorrectly perceive color. Amazingly, people do not realize that this change has occurred until after the cataract is removed. The darkening of the lens also may reduce night vision and require the person to use more light to read.
Glare and/or sensitivity to light: Some cataracts do not reduce acuity so that the person can see small letters on the chart, but the vision is distracted by glare from lights. Glare and halos are particularly distressing when driving at night, crossing the street in bright daylight, or working at a computer.
Because the majority of cataracts advance gradually, people adapt to these visual changes and do not notice the progressive compromise in their vision.
Common symptoms of cataracts
Because cataracts typically evolve gradually, the individual adjusts to their change in vision and does recognize the presence of cataracts. Often, the ophthalmologist is best qualified to identify the cataract and correlate a cataract's impact on the person's vision and life.
Cataracts may cause:
Blurred or cloudy vision
Glare and/or halos around lights
Double images or 'ghost' images in one eye
Color changes or fading of colors
Reduced night vision
Difficult achieving a proper spectacle correction
How is a cataract diagnosed?
Cataracts are usually diagnosed by the ophthalmologist during a comprehensive examination. The symptoms of a cataract may be elusive, and cataracts are often discovered during routine exams, or visits prompted by the person's perceived need for new glasses. In the event that the vision is compromised, other causes for this compromise must be assessed as well.
How is cataract treated?
Cataracts are treated surgically. The discovery of a cataract does not necessarily imply that surgery is needed. The visual impact of a cataract must be assessed in the context of an individual's lifestyle and needs.