Blurred vision, and seeing bright speckles in vision field, can indicate an episode of severely increased high blood pressure or it may be a sign that your vision is deteriorating due to chronic uncontrolled blood pressure.
Eyes, and every other organ in body, suffer seriously when a high blood pressure isn't controlled (hypertensive retinopathy, is manifested with vision problems and headache).

Since your lifestyle isn't risky for your blood pressure, you should be examined for some underlying cause for your hypertension and you'll need to be prescribed anti hypertensive drugs.

Best wishes!
Marija