you can train your eye to see the "blurs" using a tachistoscope
Someone who is serious about spooking the hole card can buy a tachistoscope, which is a device that can flash images at varying speeds. With a tachistoscope you can train your eye to follow images and recognize them that other people would swear are just a blur. You start out at a speed that is comfortable, then increase it a notch, then get comfortable with that, etc., until you are up to dealer dealing a card from a deck speed. The air force pioneered the use of the tachistoscope, they have found that the human eye can recognize a complex image which is very small in as little as 1/500th of a second. If you do a search on tachistoscope in google you will find companies who sell them as well as a white paper which describes using a CRT as a tachistoscope, I believe you can buy software for this purpose.
I know someone who is very short who bought a tachistoscope and practiced every day for hours, when he goes to the casino he sits at first base and slouches in his chair (pretending to be drunk) and can usually catch the hole card.
Regards,
Steve