If you take Wegovy or Ozempic, you may have heard about new warnings regarding eye health. In September 2024, the FDA updated the safety labels of both medications to include a warning about a rare but serious eye condition. For many people, this news came as a surprise — and understandably raised questions. Here is a clear, honest look at what the research actually shows, who is most at risk, and what practical steps you can take.
What is NAION and what does the research show?
NAION stands for Non-Arteritic Anterior Ischemic Optic Neuropathy. It is a condition where blood flow to the optic nerve is suddenly reduced, causing painless but rapid vision loss — usually in one eye, and often noticed upon waking. Unfortunately, the vision loss is permanent in most cases.
In 2024, a study published in JAMA Ophthalmology (Hathaway et al.) found that people with type 2 diabetes taking semaglutide — the active ingredient in Ozempic and Wegovy — had approximately four times higher risk of developing NAION compared to those taking other diabetes medications. A separate study in Ophthalmology Science found similar results.
This sounds alarming — but context is essential. NAION is a rare condition, affecting roughly 2 to 10 people per 100,000 per year in the general population. A fourfold relative increase still means the absolute risk remains very low for most people. The studies were also observational, meaning they identify an association rather than a proven cause-and-effect relationship. That said, the FDA considered the evidence significant enough to update the safety labeling for Ozempic and Wegovy in September 2024.
Why might GLP-1 medications affect the eye at all? Researchers have found that GLP-1 receptors are present in the eye — including in retinal cells. The exact mechanism behind a potential NAION link is not yet fully understood and remains an active area of research.
Who is most at risk?
Not everyone on GLP-1 medication faces the same level of risk. People most likely to develop NAION tend to share certain characteristics:
- Small optic disc with little cup-to-disc ratio — sometimes called an "at-risk disc". This is a structural feature only an eye doctor can identify, and it is the single strongest risk factor.
- Pre-existing cardiovascular disease — reduced blood flow elsewhere in the body may affect optic nerve blood supply too.
- High blood pressure (hypertension) — a known risk factor for NAION in general.
- Sleep apnea — causes repeated drops in overnight oxygen levels, which can affect optic nerve health.
- Being male and over 50 — NAION is more common in this group overall.
- A previous episode of NAION in the other eye — significantly raises the risk of a second event.
If several of these risk factors apply to you, it is especially worth discussing eye health with your doctor before starting or continuing GLP-1 treatment.
What about diabetic retinopathy?
There is a separate eye concern specifically for people with diabetes: diabetic retinopathy. This is damage to the tiny blood vessels in the retina caused by long-term elevated blood sugar — and it affects a significant proportion of people with type 2 diabetes.
When blood sugar drops quickly — as it can when starting or intensifying GLP-1 therapy — existing retinopathy can temporarily worsen. This was observed in the SUSTAIN-6 clinical trial, where 3.0% of patients taking semaglutide experienced retinopathy complications, compared to 1.8% in the placebo group.
This effect is most relevant for people who already have poorly controlled diabetes and established retinopathy. The rapid drop in blood sugar, rather than the medication itself, appears to be the key driver. People without pre-existing retinopathy are at much lower risk of this particular complication.
Are there also benefits for eye health?
Yes — and this is an important part of the picture. Over the long term, improved blood sugar control dramatically reduces the risk of developing diabetic retinopathy in the first place. For people with type 2 diabetes, this is one of the most meaningful long-term benefits of GLP-1 treatment.
The presence of GLP-1 receptors in retinal cells also suggests the medication may have direct protective effects on eye tissue. Some research points to anti-inflammatory properties of GLP-1 drugs that could benefit the retina over time. This area of research is still developing, but the early signals are encouraging.
In short: GLP-1 medications carry both potential short-term eye risks (particularly for people with existing retinopathy or NAION risk factors) and meaningful long-term eye benefits (through better blood sugar control and possible direct protective effects).
What should you do?
The good news is that there are clear, practical steps you can take to protect yourself:
- Get a baseline eye exam before starting treatment. Tell your eye doctor you are starting Wegovy, Ozempic, or Mounjaro. They can check for an at-risk optic disc and assess whether you have any existing retinopathy. This information helps your healthcare team make the best decisions for you.
- Report any sudden vision changes immediately. If you notice sudden blurring, darkening, or loss of vision in one eye — even briefly — contact a doctor or eye specialist the same day. Time matters with NAION. Do not wait for a scheduled appointment.
- Keep up with regular diabetic eye screening. If you have diabetes, annual eye checks should already be part of your care. Keep these appointments — and let your eye doctor know about your GLP-1 medication and any recent dose changes.
Should you stop your medication?
For most people, no. The overall benefit-risk profile of GLP-1 medications remains strongly positive. These medications reduce cardiovascular events, lower blood sugar, support significant weight loss, and may protect organs including the kidneys and liver. The absolute risk of NAION, while real and worth taking seriously, remains low for most users.
However, if you have multiple risk factors for NAION — especially a confirmed at-risk optic disc or a prior NAION event in one eye — it is worth having an open conversation with your doctor about whether to continue, pause, or adjust your treatment. Do not make that decision alone or stop medication suddenly without medical advice.
Conclusion
GLP-1 medications and eye health is a topic that deserves attention — but not panic. The FDA warning about NAION is there for a reason, and the research linking semaglutide to increased NAION risk is real. At the same time, for most people taking Wegovy, Ozempic, or Mounjaro, the benefits of treatment are substantial and the absolute risk of serious eye complications is still low.
The most important thing you can do is be informed: get an eye check before you start, keep your follow-up appointments, and seek help immediately if your vision changes suddenly. Working with your healthcare team — and knowing what to watch for — puts you in the best possible position.
Always speak to your doctor if you have concerns about eye health during your treatment.