- "The disorder is characterized by a sudden outburst of one or multiple sneezes when a dark-adapted person — they’ve been in a darkened space for a while — is suddenly exposed to light. Sunlight is a trigger, but artificial illumination from light bulbs and camera flashes can also cause sneezes. Additionally, a not-yet-established length of time in a darkened space — called a refractory period — must pass before an individual with photic sneeze reflex will sneeze in light again.“It’s not a disease,” University of California, San Francisco neurologist and human geneticist Louis Ptáček told the NewsHour. “Some people find it annoying, but some people like it to some extent. They’ll say, ‘It helps me get a sneeze out.’”
- "As it turns out, an estimated 10 to 35 percent of the population has a photic sneeze reflex. Because its prevalence is higher in individuals with a family history of the disorder, the handful of scientists who have studied the phenomena suspect a genetic, autosomal dominant — a person needs only one parent with the condition to inherit it."