One of my favourite YouTube blunders is from creator Brittany Broski, who complained to drag queen Trixie Mattel (busy giving the online star a heavy-lashed makeover at the time): “When I close my eyes, I can’t see.”It’s hard not to laugh at Trixie’s disbelieving “Well...”, given that we all know the world goes dark when we lower our lids.Except ― does it? While we clearly can’t “see” the real world when our eyes are closed, many of us do start to notice patterns, shapes, and colours when our retinas are deprived of light. Why is that, how common is it, and what does it mean?It’s technically a hallucination According to health information site Healthline, these are called “closed-eye hall