In the body
Vision changes
Sudden vision loss in one eye is an emergency. What's known about the eyes on these medicines.
Sudden vision loss in one eye is the one sign to know, so it comes first.
When to get care
Now
If you suddenly lose vision in one eye, fully or partly, even without pain, get care right away, the same day: an eye doctor or an emergency service.
A very rare eye problem called NAION has been linked to semaglutide. Eye specialists advise immediate evaluation.
Now
If you use insulin or a sulfonylurea and get cold sweats, shakiness, sudden hunger, a racing heart or blurred vision, follow your doctor's low blood sugar plan right away.
Sulfonylureas include glibenclamide (glyburide), glimepiride and gliclazide.
Now
If someone on insulin or a sulfonylurea becomes confused, faints, has a seizure, or can't be woken after drinking, call emergency services now.
Heavy drinking, especially without eating, and hard training without adjusting food are known triggers of low blood sugar for them.
Soon
If you have diabetes with eye damage (retinopathy) and notice any change in your vision, talk to your doctor without delay.
In a large trial of semaglutide in type 2 diabetes, retinopathy complications were more frequent, especially in people who already had it.
What's known
A very rare eye problem, sudden damage to the optic nerve called NAION, has been linked to semaglutide. It's listed as a very rare side effect in the European and Brazilian labels, and the UK regulator issued a warning in 2026. The US label doesn't list it.
Eye specialists don't recommend routine eye checks just because you take these medicines. General risk factors they cite include high blood pressure, diabetes, sleep apnea and blood vessel disease.
If you have diabetes with retinopathy: in a large trial of semaglutide in type 2 diabetes, retinopathy complications happened in 3.0% of people against 1.8% on placebo, and in 8.2% against 5.2% among those who already had retinopathy. The labels ask for follow-up in that case.
To take to your appointment
- I have diabetes and retinopathy. How should my eyes be followed during treatment?
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