Oh the improvement was noticed immediately. Just one night's proper sleep or not wearing spectacles and keeping the eyes closed, gave relief. Even the consumption of meat giving more strength to the eye muscles, was noticed early-on. However, since my strain was chronic, and since I continued using the computer for long hours and since I had to wake very early for work, the soreness of the muscles persisted and it never really got a chance to heal. The continued soreness was what initially made me and the doctors think that just taking rest and getting proper sleep was not enough. So we went along the long winding path of trying eye drops, new spectacles, and a bunch of nonsensical advice from friends, relatives and colleagues. At that point of time, nobody knew the right way to cure it, and how long it'd take to get cured. If I had taken a sabbatical from work back in 2012, and ensured that I got proper sleep, rest and nutrition, I'd estimate I could have recovered in one or maybe two years (because the strain was that severe). It was only by 2016 and 2017 that my experiments led me to start taking more drastic measures to ensure that I got proper rest. Ever since I started getting better rest and sleep, I could notice measurable improvements every year or so. Now I'm seeing measurable improvements every four to five months. I reason that the speed of recovery depends on the quality of sleep, rest, nutrition, age, how long the strain was prolonged and the severity of strain. I dearly hope people would do more research on this and come up with useful metrics.