Contrary to the popular belief, squinting is not bad for your vision. In fact, squinting enhances your level of focus as your pupil gets smaller due to less light entering the eye. While squinting poses no risk to your eye health, it can cause headaches and eyestrain. Squinting may be a sign that you have a refractive error, such as nearsightedness or farsightedness that is causing blurry vision. Treatment options include glasses or contact lenses to help restore your vision.