Reposting this from the BackTo20/20 forum, for our resident darling nerds.
This is more of a fun mathematical based question instead of a progress report or update. It’s based on CM measurements.
While taking walks I usually like to count how many paces from the point at which I can read a car’s license plate to when I reach the car. My max pace with my last normalize was 50 paces (could be a little more, since it was a casual count, but repeated). It varies though, and a lot of times it’s 40+ paces (I think things like the heat wave coming off the asphalt on the road can interfere). A quick measurement I just did shows I do about 8.5 paces per 20 feet.
When running some numbers, I realized that diopters are very easy to calculate: just 100/your centimeter. You have provided the formula on the website somewhere, but I think it was a bit longer (converting for meters). Anyway, I realized that this is one of those infinite slope things because if you divide 100/2000 you still don’t get 0 (ie. “perfect vision”). So, since 100/800=0.125D I figured that that is a good number to start with to gage for “good natural vision.”
When working out the formula, I got:
800 cm = 26.25′
26.25’*(20’/8.5 paces) = ~62 paces
Hence, “good vision” for me with full prescription would give me 62 paces being the point at which I can read a car’s license plate outside in ideal conditions (sunny, but without squinting, and no heatwave coming off the asphalt).
Again, the max I’ve had with norms is 50 paces.
This translates to less ideal conditions (heat wave interference) of 40+ paces.
New norms (like the ones I just started wearing from yesterday) gives me about 35 (measuring in the less ideal condition mentioned above).
Does all of this seem valid to you? If it is, this means I’d need to be more accurate with my paces (double check pace distance, and counting in various scenarios). Hope it makes sense, though, because for me it might be a fun way of logging data improvement via real world experiences.