Question
Dear Margaret, I have this ability to blur my eyes on demand and then make them go clear again with thinking about it. i did this wehn looking into the autorefrector machine at the opticians and i think it gave me a higher presciription for short sightedness, as two years ago i was -.50 and now its like -1.25, the optician gave me the -1.25 as although i felt i didnt need it, things looked mch crisper with it, when i blur my eyes and put my new glasses on, it makes everything clear.
my question is, is it normal to be able to do that? and why did the auto machine give me a much higher number?
thanks
Answer
Well, it is kind of assumed that you will have your focusing mechanism relaxed when they are running the autorefractor. If you were "blurring your eyes" at the autorefractor, then yes, you could wind up with too strong an Rx. I am not sure how different the refracting exam is in the UK, but in the US, the eye doctor normally does some other testing that would prove the autorefractor wrong if you had been doing this "Blurring" when they ran it.
When you ask "is it normal to be able to do that?" I would say mostly, no. I mean many young people (under forty who still have accommodation in their system) probably could do this "blurring" if they knew which eye muscles to use, but most would not. What you are most likely doing when you "blur" your eyes is pull them in (accommodate - the act engaging certain eye muscles to change focus from distance to near) so the eye muscles are focused at near. this would make you "look" more nearsighted to the autorefractor. I would not recommend wearing the -1.25 glasses if you think they are too strong. I recommend going back to the optician and explaining what happened and ask to be retested.
