The lens of the eye, which is normally clear, can become clouded, a condition known as a cataract. This clouding scatters light and results in blurred vision, faded colors, and difficulty seeing at night. While they can occur due to various factors, cataracts are overwhelmingly associated with the natural aging process of the eye.
Overall Prevalence Statistics
Cataracts represent a significant public health issue both within the United States and globally. More than 24.4 million Americans who are aged 40 or older have been affected by the condition. In the U.S. alone, eye surgeons perform between 3 million and 4 million cataract removal surgeries each year. Worldwide, cataracts are the leading cause of blindness, accounting for approximately 45% of global cases.
Prevalence by Age Groups
The single greatest factor determining a person’s likelihood of developing cataracts is age. Prevalence rates are relatively low in middle age but begin to rise steadily with each passing decade.
For Americans between 40 and 49 years old, the prevalence is about 2.5%. This percentage reaches roughly 5.2% by the early 50s and climbs to 9.1% for those aged 55 to 59.
The rate of diagnosis continues to accelerate, affecting approximately 15.5% of people in their early 60s and nearly 25% for those aged 65 to 69. By the time individuals reach the 70-to-74 age bracket, the prevalence surges to about 36.5%.
The likelihood approaches a 50% chance for those between 75 and 79, with a prevalence of roughly 49.5%. Among Americans 80 years and older, the majority are affected, with statistics showing that over half have either developed a cataract or had surgery to correct one.
Factors That Increase Likelihood
While age is the primary driver, several non-age-related factors can significantly increase an individual’s risk of developing cataracts or accelerate their onset. Chronic health conditions, particularly diabetes, are strongly linked to earlier cataract formation.
High blood sugar levels can cause structural changes in the lens of the eye, making people with diabetes up to five times more likely to develop the condition.
Unprotected exposure to ultraviolet (UV) radiation from the sun is another contributing environmental factor. UV rays can damage the proteins within the lens, leading to clouding over time.
Lifestyle habits also play a role; individuals who smoke are estimated to be two to three times more prone to developing cataracts. Smoking introduces harmful substances that promote oxidative stress within the lens.
Other factors that modify risk include a family history of the condition, prolonged use of corticosteroid medications, and excessive alcohol consumption.