As we get older, our vision changes and we are more susceptible to developing age-related eye conditions. But people shouldn't assume vision loss is a normal part of aging. It is often preventable or treatable, not inevitable. 

As the population around the globe ages, healthy aging—defined by the World Health Organization as "the process of developing and maintaining the functional ability that enables well-being in older age"—should be a priority. Many aspects of health are tied to well-being, but vision loss is one of the most impactful because it can significantly affect independence in older adults. According to estimates from the Institute for Health Metrics and Evaluation (IHME), vision loss disproportionately impacts older adults, with 77 percent of all vision loss occurring among people aged 50 and older, and 31 percent among people 70 and older.

Vision loss can occur due to a lack of available treatment for treatable eye conditions. It can also develop as a secondary condition when another disease is left undiagnosed, untreated, or poorly managed. If progress in addressing these factors is not made, a predicted 179 million more people will develop moderate and severe vision loss worldwide—a 61 percent increase—by 2050.  

Why Blood Sugar Matters

Being aware of and addressing high blood sugar (hyperglycemia) can help prevent eye disease. High blood sugar affects people with pre-diabetes or diabetes, and chronic highs can, over time, lead to problems with the tiny blood vessels in the eye, the optic nerve, and the lens. Two eye diseases, glaucoma and cataracts, are more likely to affect people with pre-diabetes or diabetes.

One telling measure of high blood sugar's impact on vision loss progression comes from a metric developed by IHME called "years lived with disability" or YLDs. YLDs are defined as the number of years lived in less-than-ideal health. In 2019, high blood sugar contributed to 9 percent of YLDs due to cataracts and 10 percent of YLDs due to glaucoma. In other words, approximately 74,000 glaucoma and 600,000 cataract YLDs occurred due to high blood sugar, and could have been prevented if high blood sugar had been addressed and managed through healthy eating, exercise, and regular monitoring.

The early diagnosis, treatment, and management of diabetes can curb progression of eye disease. One consequence of chronic high blood sugar is diabetic retinopathy, when blood vessels in the retina are damaged. If left untreated, over time, diabetic retinopathy can lead to vision loss. Approximately 60 percent of individuals who have diabetes for 10 years or more will develop some form of diabetic retinopathy; after 15 years, this percentage jumps to 80 percent. Early diagnosis and effective management of diabetes is essential for preventing complications. However, there are many barriers to effective diabetes management, including lack of access to health care and the high cost of diabetes management tools, including blood glucose monitors, blood glucose test strips, and insulin. In the United States, people with diabetes spend 2.3 times more on medical expenditures than people without diabetes. 

The nonprofit organization Beyond Type 1 reported a story of a woman named Rachel who lived with Type 1 diabetes for 27 years, but her stage 4 diabetic retinopathy was left undiagnosed until she experienced severe vision loss. Her lack of access to diabetic retinopathy screening by a specialist led to complications for Rachel. What's more, her vision loss had a detrimental impact on the treatment of her diabetes. The diabetic retinopathy altered her depth perception, which made using insulin more difficult.

Vision Loss is Not Inevitable

During this year's Healthy Eye Aging Month and the 2021 Global Week for Action on NCDs, it is crucial to consider the concept of healthy aging and how it is related to vision loss. Vision loss can be prevented by addressing risk factors such as high blood sugar, and through the proper treatment and management of diabetes, as well as screening for disease complications. In order to create a world where people can continue to see clearly as they age, we need to recognize that vision loss is not an inevitable part of aging.

EDITOR'S NOTE: All statements and views expressed in this article are solely those of the individual authors and are not necessarily shared by their institution.