|It's a Frit!|
WHAT THE FRIT? According to Superglass123.com, the frit is a black enamel band that is baked into the edges of the windshield from the factory. The Frit is a mixture of silica and fluxes that is fused at high temperature to make glass.
WHAT DOES THE FRIT DO? 1) from the inside it provides a surface that allows adhesive to bond to the glass. 2) from the outside it prevents solar UV Rays from causing damage to the glue used to adhere the windshield to the car body.
WHAT DO THE DOTS DO? The dots on the edges of your windows provide a smooth transition from the solid black frit band, to prevent distortion and to look better. The dots also create a shield from the sun, similar to having a small form of tint. The majority of the windshields come manufactured with the frit band with the dots. Some manufacturers actually use extremely small forms of their logos instead of using dots.
DOTS ON REAR VIEW MIRROR - These dots keep the sun from your eyes.