Missouri driving age restrictions

At 55 both my eyes went south almost overnight. The right eye retina started detaching. Surgeries over 4 years kept my general vision in that eye, but central vision is a no go because of a screwed up macula from any one of the surgeries. The left eye had a tear and to prevent a detachment I got 600+ laser hits. Over the years, the flotters in the left eye have dispersed and are a constant inconvenience to reading and sometimes driving during low light like dusk. The left eye is my only usable eye for near (w/reading glasses) or far vision. When my DL came up for renewal 4 years ago, I brought in a DMV form filled out by my ophthalmologist and had to take a road test, which I passed perfectly. The examiner, who had 0-5 year options for my next renewal, gave my a 5 year. Next year I have to go thru the same deal again. I don't resent this. It's the DMV's job try to keep unsafe drivers off the road. Many of us can be in denial about our shortcomings, especially age related. My brother, a year older, has it worse, with both eyes that had detachments. He went to the DMV before his renewal ad memorized the hanging eye charts. Must have worked for him this time, but since the Alzheimer's gene is also in the family, next time memory may not cut it. Don't know what I'd do if my eyesight gets so bad I can't drive anymore. I have no friends or family support, Southern California has no usable public transportation, and public services are non-existent for single males. Cities with the best public transportation, like NY, Chicago, SF, and Honolulu are all more expensive than SoCal, and 2 1/2 are just too cold.