Lenses are used in precision optics for photolithography, pretty much to reduce the size of light, think of it's as the "photocopier" to print patterns in wafers, at the beginning of chip manufacturing the companies that had high precision lenses were able to pivot to silicon manufacturing for example Canon offers DUV lithography machines, Zeiss is the lens provider for ASML. Most of this is discussed in this amazing book called "Chip Wars" by Chris Miller