Migraines are chronic severe headaches often accompanied by nausea. There is a very close relationship between the nerve pathways for vision and the occurrence of migraine attacks. Visual symptoms called aura can signal the onset of a migraine. Migraine sufferers are hypersensitive to bright light and exposure to bright light can actually trigger a migraine. Retinal migraine is a rare form of migraine with visual symptoms only in one eye.
Aura
Some migraine sufferers experience aura, an umbrella term for symptoms that predict a coming migraine. A migraine aura usually starts about an hour before the headache and lasts for 10 to 30 minutes. Although aura can occur as numbness or tingling in your extremities or your face, confusion or difficulty talking, more often people experience visual disturbances. You might perceive flashes of light, "floaters" or zigzag patterns in your field of vision, or even temporary blind spots. The visual symptoms typically start in the center of your field of vision and then radiate outward.
Light Sensitivity
Migraine sufferers are uniquely sensitive to environmental conditions like altitude, weather, noise and changes in light. In her review of the role of environmental variables in migraines in the June 2009 edition of "Headache Currents," Dr. Deborah Friedman reported that sunlight, glare or other bright light can trigger a migraine in about 30 percent of migraine sufferers. According to Dr. Friedman, migraine sufferers are hypersensitive to light when compared to other people. In an experiment using controlled levels of light exposure, migraine sufferers feel discomfort at lower levels of light than other people.
After looking at a bright light, migraine sufferers have a lower threshold for other types of pain, while other people become more immune to pain following exposure to bright light. This suggests that bright light is a double whammy for migraine sufferers, because it can not only trigger a migraine, it can also make the pain of the migraine feel worse. During an attack, migraine sufferers almost instinctively seek out dark, quiet places to rest and recover.
Retinal Migraine
Retinal migraine is a rare condition that is sometimes more broadly (and incorrectly) called ocular migraine, which can refer to migraine with aura as well. If you have retinal migraine, you experience short recurring periods of blindness or extremely poor vision, before or during the headache. Unlike migraine with aura, only one eye is affected in retinal migraine. Retinal migraines are rare, so if you lose vision in one eye, you need to see an eye doctor to rule out more serious possible conditions.
References
- Headache Currents; "Migraine and the Environment"; Deborah Friedman and Timothy De Ver Dye; June 2009
- MayoClinic.com: Migraine with Aura
- MayoClinic.Com: Ocular Migraine
