"Today I am almost blind," Impressionist painter Claude Monet wrote in May of 1922, "and I have to renounce work completely."

Six months later, he would undergo a cataract operation in an effort to restore his vision. But the artist continued to suffer spells of despair, largely because of his difficulty adjusting to changes in vision that followed the operation, according to letters he wrote to his ophthalmologist.

The letters, recently acquired by the French Ophthalmologic Society, are discussed by Dr. James G. Ravin in the Journal of the American Medical Association.

The vision problems, Ravin writes, contributed to the lack of detail and color subtlety in Monet's later works.

"It is to my great chagrin that I regret having had this fatal operation," Monet wrote to Dr. Charles Coutela when, six months after the surgery, it turned out he would need a second operation. "Pardon me for speaking so frankly, and let me tell you that it is criminal to have put me in this situation."

Monet complained that, because of the cataract glasses, objects curved abnormally and colors appeared strange. "I feel that if I take a step, I will fall on the ground," he wrote. "I see blue; I no longer see red or yellow. This annoys me terribly, because I know that these colors exist . . ."

Monet eventually adapted to his altered vision, and in 1925, a year before his death, wrote: "I am happily seeing everything again and I am working with ardor."