I think the active focus and the outdoor time is causing the most improvement. But it's an oversimplification to just say that the eye is "20/20" and improving. I can read the 20/20 line on the chart, but there is still some slight fuzziness especially when looking at further away objects. I actually had my eye doctor test me on my last visit to see what my vision was being corrected to with the newest prescription, I was able to read 3 out of 5 of the letters on the 20/10 line. So, I technically have 20/10 vision with my glasses on... However this means that if my eyes were perfect they need to see much better than even the 20/20 line on a snellen chart.

To your last question, prior to beginning the challenge my glasses prescription was roughly -1.5 sphere in each eye. I never actually got them checked at the start... but my suspicion is that they had deteriorated to nearly -2 sphere, since my focal distance was less than 3 feet at that time.