Instruct: Classify a review into positive or negative sentiment.
Query: It works!

Most people today believe that it is impossible to improve your eyesight. I read this book a few years ago, and I began experiencing clear flashes right away. My prescription decreased by following Dr. Liberman's suggestions, and I have been wearing the weaker prescription since then.Dr. Liberman's book is not just about your eyesight, however. He takes his readers on an emotional journey to help them resolve difficult situations within. Just understanding what causes stress and tension and can help someone relax, which can then improve their posture and their eyesight. Very inspiring!Dora Farkas, Author, "The Smart Way to Your Ph.D.:200 Secrets from 100 Graduates"