Transitioning from cigarettes to vapes — rather than quitting nicotine completely — is linked to a higher risk of developing severe eye diseases that can ultimately lead to blindness.
A sweeping Korean study found that swapping cigarettes for high-nicotine vapes, which are touted as a healthier alternative, raises the odds of diabetic retinopathy and other vision-damaging conditions, compared to quitting nicotine completely.
Diabetic retinopathy can lead to blindness in people with diabetes by damaging the retina’s blood vessels, while refractive disorders, which can affect anyone, such as astigmatism and farsightedness, cause blurred vision.
The broader category includes cataracts, or clouding of the lens; glaucoma, which involves optic nerve damage; and age-related macular degeneration, which involves deterioration of the central retina, all of which can cause significant vision loss.
The culprit, researchers suspect, is the nicotine itself.
Even without the tar and toxins of burning tobacco, nicotine in vapes constricts blood vessels, reduces oxygen flow to sensitive tissues and fuels chronic inflammation, taking a toll on the eyes over time.
Over the nearly five-year study period, researchers documented 6,328 major eye disease events. Complete nicotine quitters had the lowest rate at 41 cases of eye diseases per 1,000 person-years, while vapers saw that number rise to 44. The study did not include a rate for people who kept smoking cigarettes.
Overall, switching to vapes was associated with a seven percent increased risk of serious eye disease compared to quitting nicotine completely.
Roughly 19 million Americans vape e-cigarettes containing nicotine, the substance researchers believe causes blood vessel damage that leads to vision disorders (stock)
The findings challenge the notion that switching to vapes, which about 19 million Americans use, is safer.
The researchers drew on data from the Korean National Health Insurance Service, which provides universal coverage to roughly 97 percent of the country’s population.
The team identified more than 179,000 adults who had smoked traditional combustible cigarettes in 2011-2012 and reported quitting cigarettes by 2018–2019.
From that pool, they zeroed in on just over 32,000 participants. They used a statistical technique that balances groups on key factors like age, income, physical activity, and underlying health conditions to create a fair comparison between those who quit nicotine entirely and those who smoked cigarettes and switched to vaping.
Participants, who averaged about 45 years old, were followed for an average of 4.6 years.
Their health records were monitored for five major vision-impairing conditions: cataracts, glaucoma, age-related macular degeneration, diabetic retinopathy and refractive and accommodation disorders, including astigmatism, nearsightedness and farsightedness.
After adjusting for age, income, physical activity and underlying health conditions, the researchers calculated that vape switchers faced a seven percent higher overall risk of developing vision-impairing eye diseases compared to those who gave up nicotine completely.
But the risk was not spread evenly across all conditions. The strongest link emerged for diabetic retinopathy, which can lead to blindness.
Those who switched faced a 24 percent higher risk of that specific condition compared to people who quit all nicotine entirely.
Complete quitters (blue line) — those who gave up all nicotine — consistently had lower rates of vision-impairing eye diseases than switchers (red line), who quit cigarettes but moved to vapes. The gap emerged about a year after quitting and widened slightly over time, suggesting continued nicotine exposure through vapes may still harm eye health
The findings were consistent regardless of a person’s income, physical activity, weight or underlying health status, suggesting the effect that vaping has on vision is broadly applicable across different types of people.
However, the researchers caution that the cohort was nearly 98 percent male, so the results may not fully apply to women.
They also noted that the average follow-up of 4.6 years may not be long enough to capture slower-developing conditions like cataracts or macular degeneration.
The researchers say the findings, published in the American Journal of Ophthalmology, point to two main takeaways.
First, the increased risk for diabetic retinopathy likely comes from nicotine’s harmful effects on tiny blood vessels.
The link to refractive disorders may stem from nicotine’s impact on the eye’s surface and focusing ability, something earlier studies have also linked to smoking and vaping.
Second, even though the overall increase in risk was modest, it still matters because these conditions are so common.
An estimated 9.6 million Americans have diabetic retinopathy, which affects about 26 percent of all people living with diabetes. More than 150 million Americans are affected by refractive disorders.
And approximately 20 million Americans are living with some form of age-related macular degeneration.
Roughly 4.2 million Americans live with glaucoma and between 25 and 30 million have cataracts.
Researchers said that a small rise in risk can still affect a lot of people, which means doctors should talk to patients about the eye risks of switching to vapes rather than quitting nicotine completely.
