Sometimes what shines before us is the reflection of the glass

Theoretically, if we think of a window glass, the light undergoes a first refraction when passing from the air to the glass, follows its path and refracts again when passing back into the air. If after this process the light ray is not deflected from its path, it is said that the transmission is regular. If it is diffused in all directions, as in translucent glasses, we have the case of diffuse transmission.

I have always been surprised by the fact that some people buy glasses with a spectacular frame of a high price, and then put the most basic and cheapest lenses that exist, without taking into account that the most important thing is to get the best quality of vision for your eyes.