1Avoidance Of Deviation: Red green glasses is pure in color and can be completely filtered. Red and green colors complement each other, effectively avoiding detection deviation. 2Test: 4 dot binocular vision light set is able to be used for clinical test of eye suppression and amblyopia, it is a good helper for doctors to test. 3Long Term Use: 4 dot vision test light has a built in large capacity battery, which has a service life of 23 years and is able to be recharged 500 times. 4Function: Wear red and green glasses to observe 4 dot light test, and judge whether there is monocular inhibition and fusion vision function in both eyes when they are separated. 5Applicable Scenes: 4 dot vision test light is very small and can be carried around, whether you are at home or out of the house, it is very suitable for optometry places.