Optometry Board Exam Question About 'Most Common Cause of Red Eye' Sparks 200-Comment Flame War

A screenshot of a board-style multiple choice question asking for 'the most common cause of red eye in adults' has ignited a 200-comment argument on the Optometric Physicians of America online forum that has been running continuously for three days, with no resolution in sight and at least two professional relationships reportedly damaged. The question, which appeared on a practice exam for the National Board of Examiners in Optometry, offered four answer choices: allergic conjunctivitis, viral conjunctivitis, bacterial conjunctivitis, and dry eye disease. 'It's allergic,' posted Dr. Histamine IgE at 2:14 AM on Thursday, beginning the thread. 'Allergic conjunctivitis affects up to 40 percent of the population. This isn't debatable.' 'It is absolutely debatable,' responded Dr. Adenovirus Serotype within minutes. 'Viral conjunctivitis is the most common infectious cause of red eye. The question says most common cause. That's viral.' 'You're both wrong,' interjected Dr. Goblet Cell at 3:47 AM. 'Dry eye disease affects approximately 16 million diagnosed Americans and countless undiagnosed cases. Red eye secondary to ocular surface disease is far more prevalent than either allergic or viral etiologies. I will die on this hill.' The thread has since expanded to include subspecialty factions, historical analysis of board exam answer keys, citations from four different editions of Kanski's Clinical Ophthalmology (which apparently gives different answers depending on the edition), and one post consisting entirely of the word 'SUBCONJUNCTIVAL HEMORRHAGE' in capital letters from a practitioner who offered no further elaboration. Forum moderator Dr. Neutral Observer attempted to intervene at the 150-comment mark, noting that 'the answer depends on the population studied, the definition of red eye, and whether we're counting self-limiting cases.' This post received twelve angry reactions and a reply calling it 'the most fence-sitting response in the history of ocular surface disease.' The practice exam's answer key lists viral conjunctivitis. This has satisfied no one.