It may come as a surprise to readers to learn that windshield repair is a "recent" development in the history of automobiles; it really begins with the introduction of laminated glass windshields. Before that, windshields were made of special glass, which, while stiffened and thickened as much as could be without impairing vision, nonetheless broke or shattered when damaged. It's not worth it to try and repair ordinary glass under these circumstances! While there were some examples of laminated glass windshields in the 1930's, it wasn't until the 1960's with the use of polyvinyl butyral as the inner layer that laminated glass came into wider use.
It wasn't until the 1970's that true repairs became possible. Until that time all that could be done was to force some oil- based fluid into the damaged area to disguise it. The history of windshield repair technology is interesting but involved; suffice it to say here that the 3M Company of Minnesota was the first on the scene, with a VERY LARGE machine to repair bullseyes; nowadays of course we have innumerable shops that specialize in all aspects of repair.
A star break
The official vocabulary of windshield damage is interesting and important to what follows:
Generally speaking, dings that don't actually come through into the inner layer of the windshield, and cracks less that a certain size, can be repaired.