When at the optometrist, should I read the letters I can see clearly, or the ones I can make out and deduce what letter it is?

When I go to the optometrist, I generally can read the smallest line of print just by deducing that it’s a letter of the alphabet and it’s general shape, but it’s not clear at all. Should I read the smallest line that I can see clearly or, like I’ve been doing, read the smallest line I can make out?

I find myself reading things at a distance like street signs and can’t read them until I’m right at it when I feel like I should be able to read it clearly from further away.

TIA