Want to experience LSD-like hallucinations without actually having to ingest any drugs? Try staring into someone's eyes in a dimly lit room for 10 minutes. It worked for Jenni Avins, who sat down a colleague in a supply closet, stared into her eyes, and saw her facial contours replaced by the features of a mountain lion: "I cried the whole time," Avins writes at Quartz. "Then we went back to work." For the record, her colleague had roughly the same experience (she thought Avins began to resemble a lioness). This strange encounter was inspired by Italian researcher Giovanni Caputo, who gathered 40 people in a room with "low illumination" and had half of them do the long eye-stare while the other half stared at walls while sitting back-to-back, IFL Science reports. Afterward, those staring eye-to-eye said time got slower, they felt spacey, and they experienced strange hallucinations.
As reported in Psychiatry Research, 90% of them saw the other person's face deform, 75% witnessed monster-like beings, and 30% saw animals. So what's it all about? Caputo says it may be "dissociation," or a person's departure from reality: In this case, he says, the appearance of monsters or animals may come after returning from a dissociative state brought on by minimal sensory stimulation. Looking at an earlier Caputo study—of people who stared at their reflection until strange features emerged—Scientific American in 2013 put it down partly to "Troxler fading," the effect brought on by staring at a single point for a long time. But IFL Science doesn't think that applies here: "If this were to explain" the latest study, it says, "then we would expect facial features to gradually vanish, rather than having strange things appear. ... We clearly still have a lot to learn about these strange phenomena." (Meanwhile, some people are taking LSD in an unusual way.)