It’s a loose lens frame used to check someone for a glasses prescription.

I need that on a t-shirt

Seems like they’re unsure about this being causation or just correlation.

From the article: “Type 2 diabetes and high blood pressure are risk factors for NAION. It’s possible that patients with more severe diabetes or high blood pressure were more likely to be prescribed semaglutide, as it’s a highly effective drug, and that may have played into the higher rates of NAION in those cohorts.”