To Alex or any veteran Photo Reader,

I have been photoreading many book several time during the day for almost 2 months now. When I am PRing the text is becoming less blurry than it used to be. Sometimes I can see the text clearly and I try to keep it blurry. My question is:
Do I need to keep that blurry vision with the every time I am PRing ?
Does senior PhotoReader still keep that blurry vision of the text when they are PRing ?
Last, If I need to keep that blurry vision, what is the reason or explanation for using that technic ( even for senior photoreader if it applies to them too ) ?

Thanks in Advance for your response,
Apprentice.