The exact cause of migraines is unknown, although they're thought to be the result of temporary changes in the chemicals, nerves and blood vessels in the brain. Ocular Migraines are temporary visual disturbances that normally disappear on their own without treatment in around 30 minutes. Ocular migraines usually occur in one eye. Symptoms may include blurry vision, heatwaves, shimmering coloured patterns, blind spots and a reduction in peripheral vision. A headache may occur afterwards, but not always. Common causes include: Stress, High Blood Pressure, Dehydration, Low Blood Sugar, Excessive Heat, Exercise, Bending over, Smoking and certain contraceptives. Ocular Migraines are more common in women, people over 40 and people with a family history of migraines or headaches. Ocular migraines can be diagnosed by examining the eyes and asking a series of questions about the symptoms. This can rule out other conditions with similar symptoms. Treatment is not always necessary, simply resting your eyes is recommended until symptoms pass. Painkillers are recommended if you have an accompanying headache. Avoid exposure to common triggers. Because ocular migraine symptoms can occur in other medical eye conditions, it is important to seek medical advice from your GP or Eye Doctor so that further investigations can be considered. If ocular migraines are frequent, then certain medications may be prescribed to prevent ocular migraines from happening.