The performance requirements of optical lithography equipment are driven by DRAM memory chips which require a 30% reduction in line width and a three-fold increase in resolution elements every generation. Until now semiconductor chips were small enough that arrays of them could be placed in the field of a lithography lens. This placed the emphasis on higher resolution for each new lens generation. The development of the 16-Mb DRAM has changed our priorities. The next generation of memory chips and all those to follow will require substantial increases in field sizes as well as resolution and therefore a more aggressive development pace. Within only a few short generations, conventional resolution lenses will approach 500 lb in weight and $1M in cost.