Precise scientific measurements show the moon reflects, on average, about 12% of the sunlight that falls upon it. That makes it, on average, about as reflective as an asphalt driveway. But if you’ve ever looked at a thickening gibbous moon through even a moderately-sized telescope, it can appear uncomfortably bright to the dark-adapted eye.
That’s why many visual lunar observers and lunar imagers consider filters to reduce the brightness and glare of the moon so they can see finer detail during a long observing session.
 
A moon filter reduces irradiation, glare, and excess image brightness in lunar observing. It also improves the contrast between lunar albedo features. This green moon filter will screw directly into the barrel of most 1.25" eyepieces. Its green color cuts the glare of the brightly-lighted Moon and improves the contrast so it is easier for you to see faint details that might otherwise be washed out by the brightness of the lunar surface.