Patient guide
GLP-1 medications and your eyes: when to have an eye exam
Ozempic, Wegovy, Mounjaro, Zepbound and similar medicines do a lot of good for blood sugar, weight and the heart. A few eye changes have been linked to them, and in November 2026 the FDA added a warning about one of them to every medicine in this group. Most are uncommon, and a baseline exam with regular follow-up is how they are caught early.
Sudden loss or dimming of vision in one eye is an emergency, even if it is painless and even if it is only the top or bottom half of what you see. Call (609) 246-0236 the same day. If the office is closed, or you cannot reach us, go to a hospital emergency room and tell them which medication you take.
Please do not stop or change your medication because of anything on this page. That decision belongs with the doctor who prescribed it, and an eye exam gives them better information to make it.
Who should have an exam
Anyone starting or already taking a GLP-1 medication. That includes semaglutide (Ozempic, Wegovy as an injection or a tablet, Rybelsus), tirzepatide (Mounjaro, Zepbound), orforglipron (Foundayo), liraglutide (Victoza, Saxenda) and dulaglutide (Trulicity). Most of the eye research so far is on semaglutide, but the optic nerve problem described below has been reported with every medicine in the group, which is why the FDA's warning covers all of them.
An exam matters most if any of these apply to you:
- You have diabetes, especially if you have already been told you have diabetic retinopathy.
- You have macular degeneration, in either eye.
- You have had a sudden loss of vision from the optic nerve before, in either eye. Having had it in one eye raises the risk in the other, so talk to your prescribing doctor about it before you start.
- You have high blood pressure, sleep apnea, kidney disease or anemia, or you smoke. These, along with diabetes, are the usual risk factors for optic nerve problems, with or without the medication.
If you take it for weight and do not have diabetes, no one may have suggested an eye exam, because you are not part of the yearly diabetic eye exam routine. You are exactly who this page is for.
When to come in
American Optometric Association guidance places people on these medications in an at-risk group, which means a baseline exam and closer follow-up rather than any single special test. The FDA's warning does not itself require an eye exam; this schedule is the optometric guidance.
Before, or soon after, you start
An exam in the 12 months before you begin counts. Otherwise, come in within a month of your first dose.
Closer follow-up
Your interval is set at the baseline visit. It is shorter if you have diabetic retinopathy or another finding worth watching.
At least once a year
For as long as you take the medication. If you have diabetes, this can be the same visit as your yearly diabetic exam.
Already been on it for a while without an exam? Come in now. A first exam a year in is far better than none.
What these medications can do to the eye
Retinopathy can temporarily worsen
When blood sugar comes down quickly, existing diabetic retinopathy can get worse for a while before the long-term benefit of better control takes over. In the large semaglutide heart trial, retinopathy complications were somewhat more common than on placebo, mostly in people who already had retinopathy. A trial designed to settle the question is due to finish in 2027. Until then, this is a reason to be checked, and to keep your yearly diabetic eye exams, not a reason to avoid better blood sugar.
Sudden loss of blood flow to the optic nerve
Called NAION (non-arteritic anterior ischemic optic neuropathy). It usually shows up as a sudden, painless dimming or loss of vision in one eye, often noticed on waking. Sometimes only the top or bottom half of the view is affected. The vision lost usually does not come back, which is why it needs to be seen the same day.
In November 2026 the FDA required a warning about it on every GLP-1 medicine sold in the United States, after cases were reported with all of them. European and UK regulators already listed it as a very rare side effect of semaglutide. What happens to the medication afterwards differs: European advice is to stop it if the diagnosis is confirmed, the FDA asks prescribers to consider stopping it unless the benefits clearly outweigh the risk, and the American ophthalmology societies recommend deciding together with your doctors. Either way it is a decision made with the doctor who prescribes it.
Some people are born with a small, crowded optic nerve, which is the strongest known risk factor. A baseline exam tells you whether you are one of them, and gives your prescribing doctor that information before it matters.
Macular degeneration
A 2025 Canadian study of older adults with diabetes found the wet form of macular degeneration about twice as often in people taking these medicines, though it was still uncommon: about 2 in 1,000 over three years, against 1 in 1,000. Studies since then have been mixed. The evidence is weaker than for the two changes above, but if you already have macular degeneration, it is one more reason to keep your follow-up visits.
Blurry vision as blood sugar changes
As blood sugar comes down, the lens inside the eye changes shape slightly, and vision or an existing glasses prescription can seem off for a while. It usually settles within three or four months. Mention it at your exam before changing your glasses. Blur that comes on suddenly in one eye is different, and is a same-day call.
Keeping the risk in proportion
The optic nerve problem is rare with or without the medication: it affects roughly 2 to 10 in every 100,000 adults over 50 each year. In the 126 clinical trials the FDA reviewed, it occurred about 6 times per 100,000 people per year on a GLP-1 medicine and about 4 times on the comparison treatment. European regulators put it at up to 1 in 10,000 people taking semaglutide. The 2026 consensus of the American ophthalmology societies is a possible doubling of a rare event, with cause and effect not yet proven. They do not recommend an eye exam only to predict this one problem.
The baseline exam is worth having anyway. It checks for diabetic retinopathy. It records what your optic nerve and retina look like now, so a later change can be judged against it. And it catches the ordinary things an eye exam always finds.
What happens at the visit
It is a comprehensive eye exam with particular attention to the optic nerve and the retina. Everything is done here, at the same visit:
- Vision and eye pressure, with pressure measured without the puff of air.
- A wide view of the retina, about 200 degrees in one image, to look for diabetic changes and bleeding.
- Layer-by-layer scans of the optic nerve and macula, which show swelling and early change before you notice anything, and become the baseline every later visit is compared with.
- Peripheral vision testing, which records how the optic nerve is working, not just how it looks.
- A look at the size and shape of the optic nerve, to see whether it is the small, crowded kind.
Plan on dilating drops for the baseline visit, since this is the one exam where a close, three-dimensional look at the optic nerve matters most. Near vision stays blurry for about four hours, so bring sunglasses. Bring the name and dose of your medication and when you started it.
A written summary goes to the doctor who prescribes your medication, so the eye findings are part of their decisions.
Insurance: whether the visit goes through your medical or your vision plan depends on why you are coming and on your plan. Call and we will check before your appointment rather than after. Vision plan or medical insurance explains the difference.
Warning signs between visits
Call the same day
Sudden dimming, blurring or loss of vision in one eye. A dark or missing area in the top or bottom half of your view. Colors looking washed out in one eye. Do not wait to see whether it clears.
If the office is closed, or you cannot reach us, go to a hospital emergency room and tell them which medication you take.
Check each eye on its own
Once in a while, cover one eye and look at something with straight edges, like a doorframe. Then switch. With both eyes open, a good eye can hide a problem in the other one for days.
Call for an appointment
Vision that has slowly become blurrier, more trouble reading or seeing at night, or new straight lines looking wavy. These are not emergencies, but they are worth a visit before your next scheduled one.
For referring physicians
Fax a referral or office note to (609) 855-5028 with the drug, dose and start date, whether it is prescribed for diabetes or weight management, and any known eye history. We call the patient to schedule, and a written report with the baseline findings and the recommended follow-up interval comes back to your office.
If we find diabetic retinopathy, a crowded optic disc, or anything else relevant to the medication, the report says so plainly, so it can be weighed alongside the systemic benefit.
Questions?
Call (609) 246-0236 and we will be glad to help.
Khoury Eye Care, Hamilton Mall, 4403 Black Horse Pike, Mays Landing, inside LensCrafters on the second level.
Sources
The figures and recommendations on this page come from the following. Ask at your visit if you would like a copy of any of them.
- American Optometric Association. Glucagon-like Peptide-1 Receptor Agonists and Ocular Health: Guidance for Optometric Practice. 2025.
- Marso SP, Bain SC, Consoli A, et al. Semaglutide and cardiovascular outcomes in patients with type 2 diabetes (SUSTAIN-6). New England Journal of Medicine. 2016;375(19):1834-1844.
- Hathaway JT, Shah MP, Hathaway DB, et al. Risk of nonarteritic anterior ischemic optic neuropathy in patients prescribed semaglutide. JAMA Ophthalmology. 2024;142(8):732-739.
- European Medicines Agency, Pharmacovigilance Risk Assessment Committee. Non-arteritic anterior ischaemic optic neuropathy listed as a very rare side effect of semaglutide medicines. June 2025. The UK MHRA issued corresponding advice.
- US Food and Drug Administration. FDA requires safety labeling changes for glucagon-like peptide-1 receptor agonists (GLP-1 RAs) due to potential increased risk of rare but serious eye condition. Drug Safety Communication, November 9, 2026.
- DeParis S, Oke I, Gaier E, et al. Glucagon-like peptide-1 receptor agonists and the risk of non-arteritic anterior ischemic optic neuropathy: a consensus statement by the North American Neuro-Ophthalmology Society and the American Academy of Ophthalmology. Ophthalmology. 2026.
- Wang L, Volkow ND, Kaelber DC, et al. Semaglutide or tirzepatide and optic nerve and visual pathway disorders in type 2 diabetes. JAMA Network Open. 2025;8(8):e2526327.
- Shor R, Mihalache A, Noori A, et al. Glucagon-like peptide-1 receptor agonists and risk of neovascular age-related macular degeneration. JAMA Ophthalmology. 2025.