Blurry vision for 5 days, clean at medical examination

Hello @goktu, Welcome to Connect. That has to be scary for your wife and you. Sorry to hear the doctor didn't find any cause. While we wait for members with experience to respond, I thought I would share an article to see if anything sounds familiar.

"Common causes of blurry vision in one eye include refractive errors, infections, migraine, and cataracts. Most causes of blurry vision are not serious. However, it is important to consult a doctor about sudden or persistent blurry vision, as it could be a symptom of a condition that requires treatment."
--- Blurry vision in one eye: Causes, treatments, and what to do: https://www.medicalnewstoday.com/articles/blurry-vision-in-one-eye.

Did your wife see a regular doctor or an ophthalmologist? Have you thought about seeking help at a teaching hospital or major health facility like Mayo Clinic?

Hello @johnbishop , thanks for your kind wishes and the article you have shared. From the article, I couldn’t pin it down to a cause. We went to the largest university hospital in our city and sought the care of an ophthalmologist.
I should note that the blurry vision is at the left side of the eye, as she could pass the reading test. She noticed the pupil in that eye was more dilated than the other under light, and artificial light seems worse than natural light. Other than that, I don’t know why the blurry vision isn’t going away as she is using an eye drop for dryness for now.

I need to add she has mild myopia (0.5) but using a lens at the ophthalmologist didn’t change the blurry side vision, only sharpened her reading.

Have you seen the American Optometric Association's information on myopia? Just wondering if it might provide any clues to what is causing the blurriness in the one eye.
https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/myopia

The ophthalmologist’s final verdict is that the patient just realized she had myopia, hence noticing the blur, but she was actually aware of the myopia for quite a while.

If the symptoms are persisting, you could ask the ophthalmologist for a referral to a retinal specialist. It seems these symptoms should be addressed.