The causes of migraines and blurred vision

Experiencing blurred vision with a migraine can be frightening, but visual changes are usually harmless and can be symptoms of a specific type of migraine.

• Migraines cause severe, debilitating headaches that last hours or days and are often accompanied by nausea and vomiting.
• Migraine headaches pound or throb and can be located on just one side of your head or on both.
• During a migraine, you may be sensitive to light, loud sounds and odours, and you may feel dizzy.
• As the symptoms worsen, you may also experience blurred vision or blurring may occur as the pain begins to subside.

Blurred vision can also occur if you have a type of migraine called migraine with aura.

• Migraine with aura is a migraine headache preceded by visual, auditory or neurological symptoms.
• If you have an aura, your vision might blur, you might see flashing lights or you might experience numbness and tingling.
• Auras occur just before the migraine starts, although some people experience auras without getting a migraine.

During a migraine, normal blood flow patterns change, and changes also occur in the nerve pathways. Although the exact way these brain changes cause blurred vision isn't clear, they affect surrounding tissues and nerves, including those needed for vision.

Treatment for blurred vision involves preventing migraines or using medication to treat the headache soon after it starts, before the blurred vision begins.

• If you notice that stress or certain foods trigger migraines, avoiding those foods might reduce the number of headaches you get, as will exercise or meditation if stress is a factor.
• Over-the-counter migraine medications are available in stores, but this type of medication often isn't strong enough to treat the severe pain common with migraines.
• Your doctor can prescribe medications that treat pain and prevent migraines.

Blurred vision is usually temporary and gets better as your headache improves. If blurred vision continues, it could be unrelated to your migraine and be a sign of a more serious condition, such as retinal detachment or stroke, so be sure to check with your doctor.