My eyes keep going blurry only for a few seconds been going on for like two weeks now?

Usually benign: Most blurred vision that lasts a few seconds could be due to sudden low blood pressure, when you get up suddenly, irregular or fast heartbeat, when excited or drinking high caffeine drinks, and occasionally from excess mucous from allergies. Lastly, irregular tear film can also do this like in dry eye syndrome.

Sudden Blurry Vision: Painless transient episodes of blurry vision can be caused by many things at your age. Most frequent is dry eye, then blepharitis and perhaps floaters from a pvd. Whenever something alters the surface of your eye, vision can blur. One thing not to forget is to be checked for diabetes if this happens. Most importantly, be seen by your local eye specialist to help determine cause. Do not ignore.