Fact check: Pfizer vaccine causes blindness

1. Summary of the results

The claim that "Pfizer vaccine causes blindness" is not supported by the available scientific evidence. Multiple systematic reviews and large-scale studies provide a nuanced picture of ocular complications following COVID-19 vaccination:

• Rare ocular complications do occur: Research shows that approximately 42% of documented ocular complications were associated with the Pfizer vaccine, with the most common being ocular inflammatory complications (47.3%), optic neuritis (24.3%), and herpetic eye disease (14%) ^{[1] [2]}.
• Extremely low incidence rates: A large-scale study examining over 3 million patients found that retinal vascular occlusion after mRNA COVID-19 vaccination occurs at an extremely rare rate of only 0.003% ^[3].
• No established causal relationship: While individual case reports document visual acuity reduction and visual field changes after Pfizer vaccination ^[4], studies emphasize that these complications are rare and do not necessarily indicate a direct causal relationship with the vaccine ^[2].

2. Missing context/alternative viewpoints

The original statement omits several critical pieces of context that fundamentally alter the interpretation:

• COVID-19 infection poses greater risk: The research reveals that the risk of retinal vascular occlusion was actually higher after COVID-19 infection itself compared to vaccination ^[3]. This suggests that avoiding vaccination may pose greater ocular risks than receiving it.
• Benefits outweigh risks: Multiple studies emphasize that the benefits of vaccination outweigh the risks of rare ocular complications ^[1].
• Comparison with other vaccines: When compared to other vaccines like influenza and Tdap, mRNA COVID-19 vaccines showed no significant increased risk of retinal complications ^[3].
• Widespread misinformation context: Research indicates that 83% of 637 identified items related to COVID-19 vaccines were false, highlighting the significant spread of misinformation that can contribute to vaccine hesitancy ^[5].

3. Potential misinformation/bias in the original statement

The original statement exhibits several characteristics of misinformation:

• Overgeneralization: The statement presents a rare, potential side effect as a definitive, common outcome, which contradicts the scientific evidence showing extremely low incidence rates.
• Lack of context: The statement fails to mention that ocular complications from COVID-19 infection itself are more common than from vaccination, creating a misleading risk assessment.
• Absolute causation claim: Using "causes blindness" implies a direct, established causal relationship, whereas the research shows only rare associations without proven causation ^{[2] [4]}.
• Part of broader misinformation pattern: This claim fits within the documented pattern where the majority of COVID-19 vaccine-related information circulating is false ^[5], and such misinformation has been shown to reduce vaccination intent ^[6].

Anti-vaccination groups and individuals spreading health misinformation would benefit from society accepting this narrative, as it could increase vaccine hesitancy and support their ideological positions, despite the overwhelming scientific evidence supporting vaccine safety and efficacy.