Optical bonding refers to a protective glass that is glued in front of a display to enhance its readability where installed in high humidity outdoor environments.
Optical bonding is the use of an optical-grade adhesive to glue a glass to the top surface of a display.
The main goal of optical bonding is to improve the display performance under outdoor environments.
Contrast means the ratio of the white level to the black level; in other words, the contrast ratio of display means the difference of light intensity between the brightest white pixel and the darkest black pixel.
The main purpose of optical bonding is to increase the display's contrast ratio by reducing the amount of reflected ambient light.