10 Horror Movie Moments More Terrifying When You Know The Truth

10. Bill's Death Left Harry Crosby Partially Blind For Months - Friday The 13th

The penultimate death in the original Friday the 13th sees camp counselor Bill's (Harry Crosby) corpse be discovered by Final Girl Alice (Adrienne King), his brutalised remains pinned to a door with his throat cut and an arrow sticking out of his eye.

To achieve the effect of Bill being shot through the eye, actor Harry Crosby - son of Bing, believe it or not - wore a makeup prosthetic over said eye, but due to the low-budget nature of the production, makeup designer Tom Savini ended up using cheap, unsafe ingredients for fake blood.

This included the wetting agent Kodak Photo-Flo, which then seeped from the prosthetic eye into Crosby's real eye, causing him to feel intense pain and be rushed to the hospital.

According to Crosby, he was left blind in this eye for around six months, though thankfully made a full recovery eventually. Savini, for his part, later said that this "wasn't a proud moment" for him.

And so, whenever you marvel at that gnarly gore effect in the future, know the real pain and months of trauma that went into it.