hi, what you are describing is typical of a few diseases. it could be due to causes in the neck itself, most commonly arthritis in the neck bones (also known as cervical spondylosis) may be causing compressing on a nerve of two around them leading to pain, or they may be compressing the blood vessels carrying blood to your brain, causing pain and blurring of vision. the blurring of vision could also be due to a low blood pressure if you ran too much without replacing body fluids properly causing your blood pressure to drop. or it could be something in your brain itself causing blurring or maybe even glaucoma (a disease of the eye which can be an emergency) you have to ask yourself if this is the first episode of such symptoms or have they been recurring. i do recommend getting examined by a general physician first to get a hint into what may be the cause of the problem and if required a specialist referral to an orthopedician for the neck problem or a neurologist for the headache , or even an ophthalmologist for the eyes could be organised. regards/