The purpose is to investigate whether the Blue Cut for Night filter is better at reducing migraine compared to the FL-41 filter or a filter blocking light below 500 nm. A control group will use clear lenses without filter. This is a controlled, randomized and double-blind trial.

Migraine is a neurological disorder that often causes severe, throbbing headaches that can be accompanied by nausea and vomiting. In addition, sound or light sensitivity is often seen. An attack can last up to 72 hours. Migraine can occur in one half of the head and is exacerbated by physical activity. There are several different types of migraine, of which the inherited migraine typically cannot be cured. Migraine affects about 15% of all adults worldwide, but about twice as many women as men.

About 10% of diagnosed patients have chronic migraine, which is characterized by at least 15 days of severe headache each month. Many patients have tension headaches between attacks.

Migraine most often starts in the most productive years of life, between the ages of 20 and 50, and most affects the age group of 35-54 years. For many women, migraine debuts after childbirth, while others experience that it disappears after childbirth. Several women experience that they get migraine when they have their period. This migraine is called hormonal and can follow them for many years.

Several studies have shown that migraine attacks are triggered by light, and many become very light-sensitive during an attack. So far, a FL 41 lens, which excludes blue-green light, has been the only migraine-specific optical treatment.

A new lens called "Blue Cut for Night Glass" has in a study resulted in participants experiencing less migraine. For 4 weeks, 10 participants used only the lens in the evening. Results showed that they had fewer days with headaches. The lens is so new that it has not yet come into regular production and trade. In connection with the present study, the investigators have received 13 sets of lenses.

For many years, FL-41 has been the preferred filter lens for the prevention of migraine attacks, since it was first successfully tested on children in 1991. Since this study, much has happened in terms of the development of filter lenses.

The purpose is to investigate whether the Blue Cut for Night filter is better at reducing migraine compared to the FL-41 filter or a filter blocking light below 500 nm. A control group will use clear lenses without filter. This is a controlled, randomized and double-blind trial.

Inclusion criteria:

• Adult individuals below the age of 66.
• Diagnosed with migraine by a neurologist.
• Able to communicate in Danish
• Able to voluntarily come to the clinic during an untreated migraine attack.
• Must have had migraine attacks for more than 1 year.

Exclusion criteria:

• Fewer than four migraine attacks per month.
• Chronic neck pain
• Chronic headache
• Chronic use of opioids
• Presence of a pathological eye condition (in the study, an eye condition is defined as a permanent eye condition that affects the front and back of the eye, such as glaucoma, age-related macular degeneration)
• Other acquired and congenital retinal diseases must not be present.
• If there is more than 1 line of deviation on the Snellen chart from habitual correction to best correction, the participant must have a new pair of glasses made at their own expense.

Participants will not meet each other. Outcome assessors and participants will not know which type of filters are used.