FL-41
Also called FL-41 tint, rose-tinted lenses
FL-41 is a rose-colored spectacle tint used to ease light sensitivity, most often in migraine and benign essential blepharospasm. It absorbs much of the blue-green end of the visible spectrum and passes most red light.1
Blue-green light near 480 nm is the peak sensitivity of melanopsin, the photopigment of the intrinsically photosensitive retinal ganglion cells.2 Signals from these cells reach thalamic neurons that also carry headache pain, which offers one explanation for why light worsens a migraine.3
FL-41 is best judged against a plain gray lens of similar darkness, because any lens that dims light can ease light sensitivity. In blepharospasm, patients in a small crossover trial rated FL-41 above gray, but in a larger study, light-discomfort thresholds rose equally with either lens.1,4 Avulux, a newer migraine lens, removes two narrow bands near 480 and 590 nm instead of tinting the whole lens rose.5
More detail
The FDA authorized Avulux in August 2026 through the De Novo pathway, as a class I over-the-counter device to lessen the impact of light sensitivity in people 12 and older with episodic migraine.5 Its one published trial, run by the company with 78 participants, did not meet its primary goal of greater pain relief at two hours; the benefits it reported came from analyses chosen after the data were in.6
In a four-month trial of 20 children with migraine, those wearing rose lenses went from 6.2 to 1.6 headaches a month, while those wearing a blue tint of matched density did not improve.7
The FL-41 lens in the blepharospasm trials passed about 22 percent of visible light. That is too dark for night driving, for which a lens should pass at least 75 percent.1,8
Sources (8)
- Blackburn MK, Lamb RD, Digre KB, et al. FL-41 tint improves blink frequency, light sensitivity, and functional limitations in patients with benign essential blepharospasm. Ophthalmology. 2009;116(5):997-1001.
- Lucas RJ, Peirson SN, Berson DM, et al. Measuring and using light in the melanopsin age. Trends Neurosci. 2014;37(1):1-9.
- Noseda R, Kainz V, Jakubowski M, et al. A neural mechanism for exacerbation of headache by light. Nat Neurosci. 2010;13(2):239-245.
- Adams WH, Digre KB, Patel BC, et al. The evaluation of light sensitivity in benign essential blepharospasm. Am J Ophthalmol. 2006;142(1):82-87.
- US Food and Drug Administration. De Novo classification order DEN250026, Avulux. Granted August 21, 2026.
- Posternack C, Kupchak P, Capriolo AI, Katz BJ. Targeting the intrinsically photosensitive retinal ganglion cell to reduce headache pain and light sensitivity in migraine: a randomized double-blind trial. J Clin Neurosci. 2023;113:22-31.
- Good PA, Taylor RH, Mortimer MJ. The use of tinted glasses in childhood migraine. Headache. 1991;31(8):533-536.
- College of Optometrists. Guidance for professional practice A309: tints and driving.
Reviewed October 2026
Through the lens
This FL-41 lens passes about 30% of visible light. The lens in the blepharospasm trials passed about 22%, so FL-41 lenses vary in darkness. Curve: Brain Power FL-41, digitized from a published figure (Spitschan 2019, Blackburn 2009).
Simulated from the lens’s transmission curve.