By 2050, around 2 million Americans will be legally blind, new research estimates.
Lead researcher Dr. Rohit Varma, director of the Roski Eye Institute at the University of Southern California, and colleagues recently published their findings in JAMA Opthalmology.
The team notes that rates of visual impairment (VI) and blindness have been increasing across the globe, largely due to the aging population; such problems are more common among older individuals.
Tracking the number of people who have VI and blindness is important, according to the authors, since such conditions may increase the risk of other health conditions.
"In particular, individuals who are visually impaired or blind have a higher risk of chronic health conditions, unintentional injuries, social withdrawal, depression, and mortality," say the researchers.
For their study, Dr. Varma and colleagues analyzed data from six large, population-based studies of VI and blindness, involving adults from the U.S. aged 40 and older.
Applying 2014 U.S. Census projections of VI and blindness to the pooled data, alongside population growth projections, the researchers estimated the prevalence of the conditions between 2015-2050.
By 2050, 2 million Americans will be legally blind
Results revealed that in 2015, around 1 million Americans were legally blind - defined as having 20/200 vision or worse. This means that for clear vision, a person would need to be 20 feet or closer to an object that an individual with normal vision could see clearly from 200 feet.
By 2050, the team estimated that the rate of blindness will double; around 2 million Americans will be legally blind, with prevalence of blindness rising around 21 percent each decade.
In 2015, the researchers calculated that 3.2 million Americans were visually impaired - defined as having 20/40 vision or worse with the best-corrected visual acuity.
Over the next 35 years, the team estimated that the prevalence of VI will increase 25 percent each decade, doubling to 6.95 million by 2050.
Around 8.2 million people in the U.S. were estimated to have VI as a result of correctable refractive error - defined as errors that can be corrected with glasses, including myopia (nearsightedness) and hyperopia (farsightedness).
Again, the researchers found that prevalence of correctable VI is likely to double by 2050, affecting around 16.4 million Americans.
White women most affected by VI and blindness
Assessing prevalence rates by race/ethnicity, age, and gender, the researchers found that non-Hispanic white individuals, especially women, are most affected by VI and blindness through 2050.
"Based on these data, there is a need for increased screening and interventions across all populations, and especially among non-Hispanic white women," says Dr. Varma.
Up until 2040, African-Americans will have the second highest burden of VI, according to the researchers. After this point, it is expected that Hispanics - particularly older Hispanics - will have the second highest VI burden.
However, African-Americans will continue to account for the second highest burden of blindness in the U.S. until 2050, the team reports.
"African-Americans are at disproportionately high risk for developing glaucoma, a potentially blinding eye disease that typically causes the loss of peripheral, but not central vision, so people tend to not realize that they are losing their vision and do not seek treatment," notes Dr. Varma.
Overall, the researchers believe their results highlight the importance of regular eye screening for early eye disease and correction of refractive errors among the U.S. population.
"These findings are an important forewarning of the magnitude of vision loss to come. They suggest that there is a huge opportunity for screening efforts to identify people with correctable vision problems and early signs of eye diseases.
Early detection and intervention - possibly as simple as prescribing corrective lenses - could go a long way toward preventing a significant proportion of avoidable vision loss."
National Eye Institute Director Paul A. Sieving