Squinting, straining can produce a temporary increase in clarity but this results in causing more impairment.
Dr. Bates had his patients produce strain, blur, use the eyes incorrect so they know what causes unclear vision and can then avoid it by doing the right things. Like a child that accidently burns its hand on a fire, stove... quickly the brain is programed not to do that again.
Mary I. Oliver - 38 years practice, teach Natural Eyesight Improvement.
Free on-line Better Eyesight Magazine with Translator, Speaker;http://www.cleareyesight.info/naturalvisionimprovementoriginalandmodernbatesmethod/http://www.cleareyesight.info