Pregnancy can cause the following which can cause blurry vision (from most common to least): 1. Dry eyes from hormonal changes (see email@example.com for lid hygiene instructions to help prevent this) 2. Change in glasses prescription: see eyeMD to see if Rx has changed 3. Pre-eclampsia/Eclampsia (rare): but is dangerous to mom & baby so have your BP checked & urine protein checked ASAP.
Preeclampsia is when a pregnant woman develops high blood pressure and protein in the urine after the 20th week (late 2nd or 3rd trimester) of pregnancy.