@ J4
Your problem seems that your contacts do NOT FIT WELL on your corneas. Drop the Optician and go see an Optometrist (or even an Ophthalmologist).
Btw, only the central portion of the contact lens is truly a lens... Now, when you look at a sharp angle, this might cause blurriness as the lens might not be centered well on your cornea.
Also, the varying degrees of of blurriness you describe is again due to misfitting (it seems the contacts are so misfit that even blinking can cause them to move out of centre enough to cause noticeable blurriness).
It all has to do with the fitting AND the brand (as well as good contact lens hygene: NEVER sleep in them REGARDLESS, never get water in your eyes while wearing them, etc).
Finally, some eyes are just not created for contacts (no contacts would fit them well regardless). It could be worse... some people upon wearing contacts, their eyes turn blood-shot immediately or get an itch, etc (by the way: NEVER rub your eyes while the contacts are in... this might slightly scratch the outer layer of the cornea and might even lead to severe cornea infection).
PS. My contacts are PureVision and the cleaning solution is Clear Care.
http://www.clearcaresolution.com/