Blur adaptation (or blur desensitization, sometimes called badaptation around these parts) is where someone has become used to lower levels of correction on either a psychological or physiological level.
It usually occurs after someone has been wearing significantly undercorrecting glasses, or no correction for long periods of time when they should have been wearing more correction. This causes active focus to fail, as the demand is too high, and is fixed by increasing to an appropriate level of correction.
When you live next to the train tracks and the train always goes by, people say "you get used to the noise." Blur adaptation is the same thing but with blur instead of train noises.
Avoiding Blur Adaptation
There is no benefit to living in excessive blur, many people do this thinking that it will give them a larger capacity for improvement, and/or the ability to improve faster. This is not only not the case, but frequently the opposite of this notion is true and the excessive blur slows progress, if not stalling it altogether. It is highly important to be sure you are getting good stimulus by using correction that provides only a little blur that you can actively clear with active focus; and be sure to be mindful to clear that blur to avoid becoming accustomed to it's presence. Remember, correction is a tool, and EndMyopia principles require that correction is leveraged properly for improvement.
Resolving Blur Adaptation
If you are, or suspect you are, already blur adapted because you over reduced or even quit using correction; it is a good idea to address this issue first, before trying to move forward with EndMyopia. This usually means wearing full 20/20 correction for a time to give the visual cortex a clarity reference. This might require a gradual increase to work your way up to that correction if you have been a long time without correction. For low myopes in particular intermittent use of correction, particularly in low light might be enough. Differentials should still be used, if you require them, but it is not a good idea to try to reduce to normalized before you have gotten in that time in the higher correction, a few weeks is likely all you need. Without that clear reference and sufficient correction you might have a very difficult time finding/using active focus. Without active focus your eyes are unlikely to improve.
- Guide:Not reducing too quickly
- Blur Horizon explained | Jake Steiner
- Fixing Low Myopia Blur Adaptation if you never wore glasses | Jake Steiner