From the time my optometrist first told me I had cataracts starting, until I decided I had to do something about it, was about a year or eighteen months. Seemed to me like they progressed rather rapidly. I don't know if that time frame is typical or not.
.
I’m at either 2.5 years or 3.5 years from mine telling me I was showing signs in my dominant eye. Both eyes now based on my January exam. Hopefully I’m still a year or two off as the lenses and procedures keep improving.