fuzzy vision after reading

most of the time when i read for more than half an hour, when im stopping to take a break, my vision gets fuzzy.
its something like black and other coloured spots appearing in my field of vision.
i havent been to see a doctor yet.
normally, it wont happen immediately.
i know this because i always walk to my room to take a break, and its always only in the corridor that my vision gets fuzzy.
the distance from the corridor to the place where i read is about 9 metres.
i ignored it when it started years ago.

[John C Hagan III, MD, FACS, FAAO]

Your symptoms call for a complete comprehensive medical eye exam and glasses determination. See an Eye MD ophthalmologist-physician in the near future. In the USA find one near you at www.aao.org

JCH III MD

[slashay]

What are a few possible reasons or illness that has caused these symptoms?

[John C Hagan III, MD, FACS, FAAO]

cardiovascular and neurological diease.  Much more likely however to be a eye problem like refractive error, presbyopia, accommodative spasm
JCH MD