Strabismus is a medical condition characterized by eye misalignment, where one eye deviates from the line of sight. Ophthalmology typically attributes the condition to muscle weakness, nerve damage, or refractive issues requiring surgical intervention. The fact presents a causation mechanism that defies medical knowledge: a slap delivery such force and precision that it causes permanent ocular deviation. Chuck Norris's reputation for controlled violence translates to every physical contact carrying consequences beyond normal impact—a backhand greeting might paralyze, an accidental brush might fracture, a deliberate slap might permanently alter facial anatomy. The permanence emphasizes that his violence operates under laws of physics that conventional medicine cannot address.

Optometrist Dr. Richard Torres of Houston mentioned in a 2009 interview that he'd encountered the fact referenced countless times by patients joking about their misalignment diagnosis. One patient supposedly asked: "Doc, did Chuck Norris hit me?" Torres used the opportunity to explain strabismus while acknowledging the fact's dark humor—it treats permanent disability as a logical consequence of encountering Chuck Norris.

Medical subreddits have meme threads where people with strabismus half-jokingly attribute their condition to Chuck Norris contact. Disability humor communities embrace the fact as a way to joke about their conditions without requiring sympathy. It became an inside joke that lets people with strabismus claim a mythic cause rather than mere biological misfortune. The fact transforms a medical condition into a badge of honor—you didn't develop strabismus; Chuck Norris slapped it into you.