I suspect it did not happen overnight, but rather gradually over the past few years. Genetics might play a major role. Excessive sunlight, unhealthy lifestyle with smoking, poor nutrition, lot of drinking, as well as certain medications especially steroids, diabetes, trauma, are factors that seem to increase cataracts in my experience.
Thankfully, you have a very treatable condition with very high surgical success rate. You should great.
Michael Kutryb, MD
Well, I'm 63 and thought how can this be happening to me? Thought it was only old people who had cataracts. HaHa. Any way, left eye was fixed a week ago with a Tecnis acrylic aspheric. Couldn't tell its not my normal eye of 40 years ago, except that now the focus is fixed at about 13-14 inches. No problema, cause I've worn specs for 43 years and the multifocals work just fine. Actually I still find it hard to believe how easy, painless, and effective the surgery and lens implant has been. Good luck.