What is the blue dot in the upper right corner of the front camera of vivo Y3 mobile phone?

This is a small blue dot, which we call "dazzling light"

Glare in professional photography is often considered as a reflection of poor lens quality, and general lenses will use coating to suppress glare; However, in the film industry, glare is also used to create a unique sense of lens, so the existence of glare is a matter of opinion. In order to reduce glare, almost all modern lenses are coated with a very thin chemical film on each surface of each unit to reduce the reflectivity of these surfaces. Although coating can reduce glare, it can't completely eliminate glare; This is especially true when the lens is aimed directly at a very bright light source, such as the sun or floodlight. Since we know that the front and back of the camera lens may be coated, we should be extra careful when cleaning both ends of the lens. A rough wipe will remove the coating.