LPT Resist the habit of trying to see better during your eye exam.

If you need glasses, you're probably used to squinting to try to see better. It's really hard to break this habit, and it's even harder to remember to stop doing it during your vision exam to determine your eyeglass/contacts prescription.

I have caught myself several times squinting or otherwise trying to decipher the next line down rather than just saying "I can't read that one without squinting."

I'm so used to trying to make things clearer (or maybe subconsciously trying to "pass" the test) that I just inadvertently make my prescription weaker than it should be.