It s basically the same principle used by the laser card but instead of creating a light filter in a small localized area it creates a light filter across your entire field of vision.
Laser you can see in daylight.
Outside in full sun you will not be able to see the laser dot more than about 10 or so meters 30 feet.
Lasers red or green are for dark targets in marginal light.
In some circumstances you may not be able to see it more than 3m 9 feet.
Laser glasses effectively filter your vision to limit the light you see making it easier for you to identify your laser beam in daylight.
Stability for outdoor viewing an often overlooked aspect to daylight and outdoor projector use is the stability of the projector.
Neither is visible enough in daylight for rapid acquisition.
Laser distance measure generally has a laser output of less than 1mw class 2.