What are Cataracts?

Types of Cataracts

The lens of the eye can change in multiple ways, all resulting in the condition we call a cataract. When we develop cataracts as a natural function of aging, we are most likely developing nuclear cataract, but there are many other types as well.

The Human Lens

Nuclear & Cortical Cataract

When the eye develops a nuclear cataract, the nucleus at the center of the lens is becoming or has become opaque. This is the most common type of cataract.

Symptoms most commonly associated with nuclear cataracts include blurriness and faded colors.

Know more about nuclear cataracts

Cortical cataracts occur when the transparency of the cortex, or shell, surrounding the nucleus is compromised. While not as common as nuclear cataracts, cortical cataracts are still fairly common and caused by the natural aging process.

When we develop cortical cataracts, we often become far-sighted.

Know more about cortical cataracts

Posterior Subcapsular & Advanced Cataract

This type of cataract begins at the back of the lens and spreads to the periphery or edges of the lens. A posterior subcapsular cataract can develop when certain parts of the eye are chronically inflamed or due to heavy use of some medications, including steroids.

Learn more about the sensitivity to light that is one of the symptoms of this type of cataract.

Know more about posterior subcapsular cataracts

When a cataract is considered advanced, both the nucleus and the cortex have become completely opaque, and the lens is able to transmit very little, if any, light.

Know more about advanced cataracts

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Nuclear Cataracts – Medical Detail

When we develop nuclear cataracts, the nucleus of the eye's lens becomes more curved, which increases the refractive index and causes you to become more nearsighted. Conversely, if you are farsighted, you may notice a temporary improvement in your vision. This condition does not mean your cataract is "cured." The cataract will continue to progress, and this improvement will not last.

Cortical Cataracts – Medical Detail

The lens cortex does not begin to develop until after birth. The cortex continues to grow as we age, and by the time we reach about 60, 16 percent of the lens is cortex. Cortical production makes the lens more compact and hard, or sclerotic. A cortical cataract often forms in "spokes" around the lens.

Posterior Subcapsular Cataracts – Medical Detail

Because light converges at the back of the lens (the posterior pole) as it moves through the eye, a posterior subcapsular cataract affects vision even more than other types of cataracts. Anything that causes our pupils to constrict, such as bright light or the convergence of the eyes for reading, makes it very difficult for people with this type of cataract to see. Unlike people with nuclear cataracts, patients with subcapsular cataracts often benefit from the use of dilating drops to keep the pupils large and thus allow more light into the eye.

Posterior subcapsular cataracts can be caused by chronic intraocular inflammation or chronic use of medication such as corticosteroids. Less commonly, this type of cataract may be caused by radiation or trauma.

Advanced Cataracts – Medical Detail

With an advanced cataract, the lens has become completely opaque. When a cataract has reached the advanced state, symptoms are severe, vision is extremely compromised, and treatment becomes more difficult though not impossible.

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