Insurance doesn't cover it, so some doctors don't bother with it. I was caught by surprise when I tried out my wife's ophthalmologist. Dilation only, no option for a digital scan, my choices were get dilated or get out. I'm not going back there.
Even as they did the multiple exposures, I was wondering if I was getting suckered, but when the doctor showed me what she could see in the digital images and that she could use them to track any changes over the years, I felt really good about spending the money.