Is it an urgent situation that requires treatment for flashing vision symptoms?

A few days ago, I suddenly started to experience flashes of light in front of my eyes and a feeling of momentary loss of focus.

At first I thought it was just because I was tired, but I started to get anxious because it kept happening even after I got plenty of rest.

People around me said it could be an intraocular pressure problem or a retinal problem, so I was more worried than I should have been.

I'm curious about the basic tests performed at an ophthalmologist, such as a fundus exam and intraocular pressure test, in addition to a visual acuity test. If any problems are found during the exam, I'd also like to know whether treatment should be initiated immediately. I'd also like to know how lifestyle and eye care habits can help alleviate symptoms.