Do Ozempic and Zepbound cause blindness? What studies say

Key Points

• Ozempic, Zepbound, Wegovy, and Mounjaro may be linked to vision problems
• Research shows an increased risk of NAION (a type of eye nerve stroke) and other serious eye conditions
• Studies have not yet proven these weight loss drugs directly cause vision issues
• If you experience any vision changes, stop the medication and contact your healthcare provider immediately

In what some are calling "Ozempic blindness," new studies show vision changes in some people taking Ozempic, Wegovy, Zepbound, and Mounjaro.

These diabetes and weight loss drugs have helped many control their blood sugar and lose weight, but they're still relatively new—and research continues to reveal more about their potential side effects and risks.

"If you're taking semaglutide or tirzepatide medications and haven't noticed any changes in your vision, there's no immediate cause for alarm. However, it's important to stay vigilant," says Gia Eapen, MD.

Let's look at what the research tells us and what these findings may mean if you're currently taking these medications.

What does the latest study say about “Ozempic blindness”?

A small study published in January 2025 has sparked a larger discussion about potential vision problems in patients taking popular weight loss medications like semaglutide (Ozempic, Wegovy) and tirzepatide (Zepbound and Mounjaro).

The review examined nine patients who experienced vision changes while using these diabetes weight loss medications—known as GLP-1 drugs.

In this study:

• 7 people developed a rare but serious condition called NAION—essentially a stroke in the optic nerve—which can cause sudden, irreversible vision loss
• 1 person experienced optic nerve swelling, which can permanently damage the nerve responsible for sending visual signals to the brain (bilateral papillitis)
• 1 person developed a specific type of retinal damage that affects central vision (paracentral acute middle maculopathy)

However, the connection between these medications and vision problems isn't yet clear. The researchers themselves acknowledge they can't definitively say whether the drugs directly caused the vision issues.

Before drawing firm conclusions, several important factors need consideration:

• The review is of 9 patients only
• The study hasn't undergone peer review—a crucial process where independent experts evaluate the research quality.
• Additionally, since all nine cases came from a specialty eye center, these patients might have already faced higher risks for vision problems.

The findings add to growing discussions about potential vision-related side effects of GLP-1 medications, but more extensive research is needed to understand the true risks.

Does Ozempic cause blindness? What other studies say

Study out of a hospital affiliated with Harvard

A study out of Harvard from July 2024 sheds more light on vision-related outcomes in people taking Ozempic and Wegovy. Researchers looked at medical records from 16,827 patients, comparing those who took semaglutide against people using different diabetes or weight loss drugs.

The data shows that while vision issues were rare, certain groups faced higher risks. People with diabetes who took semaglutide were four times more likely to develop NAION than those using other medications. For patients who were overweight or had obesity along with high cholesterol, that risk increased to seven times.

Please note that while this large study offers important insights, it’s still not peer-reviewed.

Two studies from Denmark found twice the risk of NAION with Ozempic (semaglutide)

Two studies from the University of Southern Denmark in December 2024 add more context to these vision-related concerns.

In one study, researchers analyzed records from more than 424,000 patients across Denmark and Norway. They found that people with type 2 diabetes taking Ozempic had twice the risk of developing NAION compared to those not using the medication. The research team also noted an increase in NAION cases since Ozempic became available in Denmark.

A second study comparing Danish and Norwegian patients taking Ozempic against those using other diabetes medications confirmed these results—showing doubled risk for those taking Ozempic.

However, the researchers emphasize an important point: this side effect is very rare. They note that its frequency and severity are similar to rare side effects seen with many commonly used medications.

How does Ozempic lead to NAION and other vision-related issues?

Scientists don't fully understand the connection between these drugs and vision problems, but they have some theories.

Dr. Eapen explains, “When medications like Ozempic lower blood sugar—crucial for managing diabetes—a quick drop might disrupt blood flow in the tiny vessels feeding the optic nerve, potentially triggering NAION”.

As for how these drugs affect the optic nerve, scientists aren't sure yet. One theory suggests that they change blood flow to the optic nerve, which can trigger fluid shifts or inflammation in the eye.

It's worth noting that people with type 2 diabetes already have a higher chance of developing eye problems, making it hard to separate medication effects from diabetes-related changes.

Plus, Ozempic, Wegovy, Zepbound, and Mounjaro list vision changes as possible side effects.

What should you do if you’re concerned?

Dr. Eapen says, “If you’re taking Ozempic, Wegovy, Zepbound, or Mounjaro and haven’t noticed any changes in your vision, there’s no immediate cause for alarm. However, it’s important to stay vigilant. Watch for any sudden changes, such as blurriness, altered color perception, or loss of peripheral vision. If you experience any of these, stop your medication and contact your healthcare provider immediately.”

Final thoughts

Growing evidence about vision changes in patients taking weight loss and diabetes medications like Ozempic and Zepbound raises important questions. But it's worth noting that none of these studies have been reviewed by other medical experts yet—a key step in confirming their findings. While early results have caught doctors' attention, we need more research to fully understand these effects.

Health agencies are already looking into these potential risks. For now, the best thing to do is stay aware of any vision changes and talk openly with your doctor about any concerns.

It’s hard to lose weight and lower blood sugar levels on your own. Consider working with a registered dietitian, covered by your insurance, for personalized guidance. 

The views expressed by authors and contributors of such content are not endorsed or approved by Fay and are intended for informational purposes only. The content is reviewed by Fay only to confirm educational value and audience interest. You are encouraged to discuss any questions that you may have about your health with a healthcare provider.