A scientist with bad vision experiments with the power to miniaturize animals. He invites a group of scientists to his jungle laboratory to solve a minor problem, and when they don't leave after he's finished with them, he miniaturizes them.
This is a solid SF adventure flick from one of the directors of KING KONG, and though I don't consider it a real classic, it's certainly quite enjoyable. I particularly like Albert Dekker's performance as Dr. Thorkal a.k.a. Dr. Cyclops; his madness is peppered with a number of quirky traits, and he is in fact a surprisingly vulnerable individual. He is like no other mad scientist that I can think of, and this novelty gives the movie much of its appeal.

Amazon.com: VHS
Amazon.ca (Canada): VHS