When Todd Engel, based in Maryland, first noticed a change in his vision, he did not think it would change the rest of his life. However, within months, the 62-year-old went from working a full-time job and driving to becoming legally blind in both eyes. Now, Engel is suing Novo Nordisk, the manufacturer of Ozempic - the drug he believes took away his vision. An Irreversible LossEngel was prescribed Ozempic in 2023 to help manage his type 2 diabetes. After four months later, he was diagnosed with nonarthritic anterior ischemic optic neuropathy (NAION). It is a rare condition where blood flow to the optic nerve is blocked and causes sudden and irreversible vision loss. "He made a comment to me about how it’s painful to know he’s never going to see his wife smile again," said Engel’s attorney Jonathan Orent, who spoke to NBC News. "But he knows her voice so well, he can tell when she is smiling."As per the American Academy of Ophthalmology, NAION affects about 10 in every 100,000 people over the age of 50. For Engel, the diagnosis meant that he no longer would work his job as a motor equipment operator. He also lost his ability to drive and the way he connects with his family. What Does His Lawsuit Allege?Filed in New Jersey’s Middlesex County Superior Court, the lawsuit accuses Novo Nordisk of negligence, alleging the pharmaceutical giant failed to properly warn users about the potential risk of NAION. Engel's legal team argues that the company was aware of the condition during early clinical trials but still chose not to include it in the warning label.“Nothing was or is stopping Defendant from adding a warning regarding the risk of NAION,” the lawsuit states.Had Engel known about a potential link between Ozempic and blindness, Orent said, he would have chosen a different medication. “There are a wide number of medications that can be used to treat diabetes — and treat it effectively,” Orent said to NBC News.What Do Research Say About Ozempic And Blindness?Ozempic, and its active ingredient semaglutide, is part of a class of drugs known as GLP-1 receptor agonists, initially designed to treat Type 2 diabetes but now widely used for weight loss. Recent studies have hinted at a possible link between semaglutide and NAION — though causation hasn’t been confirmed.A 2024 study which analyzed six years of medical records from Boston patients found that people with diabetes who took semglutide were four times more likely to be diagnosed with NAION. Even more striking, overweight or obese people without diabetes who took the drug were over seven times more likely to be diagnosed with NAION.However, researchers noted this study wasn’t a randomized clinical trial and said more investigation is needed before drawing conclusions.In February 2024, a separate paper published in JAMA Ophthalmology reported a more modest increase in the risk of NAION for people with diabetes on Ozempic. Like the earlier study, it also stressed the need for further research.What Do The Manufacturers Say?Novo Nordisk's spokeperson told the NBC News that current evaluations, including internal safety reviews and a study from the University of Southern Denmark found no causal relationship between NAION and Ozempic. The company said that NAION is not listed as an adverse drug reaction. “This also relates to eye conditions, which are well-known comorbidities for people living with diabetes,” the spokesperson said.