A recent study has raised concerns that the Pfizer-BioNTech COVID-19 vaccine may cause subtle but potentially serious effects on the eye’s cornea, particularly its innermost layer, the endothelium. Conducted by scientists in Turkey and published in the journal Ophthalmic Epidemiology, the research examined changes in the corneas of 64 patients before and after receiving both doses of the vaccine. While no immediate vision loss was reported, the study found that the vaccine led to thicker corneas, a reduced number of endothelial cells, and structural changes that could affect eye health over time. According to the Daily Mail, experts caution that while these changes may be harmless in the short term, they could pose risks for those with pre-existing eye conditions or corneal transplants.
Pfizer COVID vaccine linked to corneal cell loss, swelling and altered structure
Researchers found that the average thickness of the cornea increased from 528 to 542 micrometers after two Pfizer doses, a roughly 2 percent rise. The endothelial cell count, responsible for keeping the cornea clear, dropped by about 8 percent, from 2,597 to 2,378 cells per square millimeter. Though this remains within a safe range for healthy individuals, such a decline could pose serious risks for those with a low baseline count due to aging, eye surgeries, or diseases like Fuchs’ dystrophy.In addition, the study noted an increase in cell size variation (coefficient of variation), rising from 39 to 42, suggesting the corneal endothelium was under stress. The number of cells maintaining a healthy hexagonal shape also dropped from 50 percent to 48 percent. As Daily Mail reported, these signs may not immediately affect vision but could compromise the cornea’s long-term clarity and function if they persist.
Scientists urge caution but do not oppose vaccination
The study, which analyzed 128 eyes using Sirius corneal topography and Tomey EM-4000 specular microscopy, does not recommend halting vaccination efforts. Rather, it calls for ongoing monitoring of corneal health in individuals with known eye vulnerabilities. The researchers emphasized that the changes observed might be temporary responses to stress or inflammation and could resolve over time.Still, they warned that “the endothelium should be closely monitored in those with a low endothelial count or who have had a corneal graft,” especially if future studies confirm long-term damage. According to Daily Mail, this adds to existing concerns over rare side effects of mRNA vaccines, including myocarditis and pericarditis, particularly in younger men. The researchers plan to continue tracking participants to determine if these early corneal changes progress or stabilize over time.
