Thirty-three patients with a history of migraines associated with photophobia were given specially made red-tinted contact lenses to insert during acute attacks. Thirty-one patients experienced rapid pain relief, of whom 26 had complete relief. For most patients, improvement began within 5 minutes, and pain relief was maximal within 90 minutes. In 5 cases, complete relief of pain occurred within 10 seconds of inserting the lenses. The contact lenses used were dark red and blocked 90% of wavelengths of 600 nm or less, while admitting 90% of wavelengths of 700 nm or more.

Comment: The investigators who performed this study hypothesized that certain wavelengths of light may over-stimulate retinal receptors, resulting in the typical migraine pain that is exacerbated by light exposure. The choice of contact-lens color was based on their earlier discovery that patients with photophobia caused by cone-rod dystrophy benefited from that type of lens. Contact lenses were chosen over eyeglasses, because eyeglasses allow glare to reach the retina through the sides and from above.

There are three types of color-sensing cones in the retina that are sensitive to long, medium, and short wavelengths of light, respectively. The lenses used in this study blocked the medium and short wavelengths, allowing selective stimulation of the long-wavelength cones. It is possible that certain wavelengths stimulate migraine pain, whereas other wavelengths inhibit it. Being in total darkness is known to provide some degree of pain relief for migraine sufferers, but selectively blocking specific wavelengths appears to be even more effective.

The investigators, Dr. Richard L. Garrison and Kathleen Saathoff of San Jacinto Methodist Hospital in Baytown, TX, acknowledge that the lens color chosen for this study may not be optimal; tints that filter different wavelengths may turn out to be even more effective.

Mahoney D. Red contact lenses help relieve acute migraine. Fam Pract News 2004(December 1):59.