Does it give a false reading if one squints in an eye exam?

Yes, don’t do that.

How much it could mess up the accuracy probably varies, but just stay relaxed.

Edit: Just throwing this out here: I thought my prescription was wrong until I was told rounder frames work better for negative (nearsighted) prescriptions. But, I am not saying that’s the problem for you. Getting rounder glasses made a huge difference for me though. Or maybe that pupil distance thing is off somehow? Just other things to consider.

If your glasses aren’t working for you, go back to the eye doctor or optician.

I always squint while reading the eye chart. I think that somehow the eyelashes somehow break ups the light to aid in bringing images into focus.

When they ask me to read the letters, I ask if it’s ok if I squint. They say no, which makes sense since they want to test the most natural vision we have – problems and all. I would trust what the doc says. There’s no such thing as middle-sightedness.

Yes. Your depth of field increases with the decreased pupillary distance. Also squinting can change your eye shape also affecting your focus point.

I meant decreased pupillary diameter, not distance.

Update I called the eye dr office. They recommended me buy some cheap +1.5 reader glasses.

I found some online for $2. I ordered. Will deliver in an hour or two.

Update Glasses arrived. They are blurry unless the book is right in front of my face. Too dark in apartment to read. Will try afternoon tomorrow.

deleting this because I confused myself and my comment makes no sense. Just go somewhere else

They’re reading glasses, so yes they’re blurry unless you’re focused on something right in front of you. If you only need glasses for reading or detail work like embroidery, they will often recommend reading glasses – you don’t need a script. It saves a ton of money.

I have 5–6 pairs of reading glasses with different strengths.

Did the reading glasses help? If the doctor recommended readers rather than a full prescription, your eyes can’t focus close-up. Apparently this is called “presbyopia” and it’s very common. The glasses help move the focal point so you can focus on stuff!