Blurry eye at the end of the day

Early in the day, my vision is fine.  But toward the end of the day, around 4pm, my eye sight becomes blurry, like looking through a piece of clear plastic.  Gradually, the blurry vision happens earlier, e.g. instead of 4pm, it is 3pm.
What is the problem?  What can I do to fix it?

P.S.: The blurry vision continues during the night.  I can not sit on the couch and see the TV clearly.

[XC44]

It could just be that your tired.
like if i read too much or work on a computer
for a while my vision will get all unfocused
the way you described.
Usually blinking helps to get rid of it
and refocus but if i'm really tired
or have been working too much
i need to sleep and I wake up
fine agai. If its bothering you
though you should see a doctor,
if nothing wrong then you wasted your co-pay and thats all