Monet developed this style not only in rebellion against the old school of painting, but possibly also because he was short-sighted and suffered from cataracts. Only after years of refusing treatment did he undergo surgery in 1923 and bought himself two pairs of eyeglasses from the optician E.B. Meyrowitz, who was located near Place Vendôme in Paris. Both pairs of eyeglasses had mineral lenses made by ZEISS: one with untinted and one with tinted lenses, each in tortoiseshell frames.
These lenses, known as “Katral” lenses, had been produced since 1912 specifically for people who had undergone cataract surgery. However, the complex manufacturing process drove the price up, so that one lens cost 40 gold marks - equivalent to the monthly rent for a comfortable four-room apartment in a prime metropolitan location. Accordingly, only relatively wealthy individuals like Claude Monet in his last years were able to afford such glasses.
However, with his new, sharper vision thanks to the ZEISS lenses, Monet was disappointed by the rather bleak colors he’d used up to that point, and painted over many of his works in brighter hues, including a part of the “Nymphéas” series of water lilies, which consisted of roughly 250 oil paintings done over a period spanning more than 30 years.