Thread: Should parallax and focus coincide ?

In the weekend, I had the opportunity to use a Zeiss Conquest 6.5-20x50. It would focus up beautiful and sharp at 100m but there was a lot of parallax apparent (5-10 cm). Adjusting the parallax knob to minimise reticle movement gave quite a blurry image - I couldn't see the scoring rings and could barely make out the aim point.

Is this a fault in the scope or a "feature" of my eye ?

I've had cataract surgery and got an intraocular lens, which is fixed focus. It has been set about 0.5 diopter short sighted to make it easier to read. For me, the "side focus" is good for getting a sharp image, while control of parallax error is a lower priority. Other shooters over about 50 will also have reduced accommodation and a naturally long sighted person would have difficulty focusing up close. Does anyone else notice a discrepancy between focus and parallax ?

Question again: Should a scope be built so that sharp focus and minimal parallax occur at the same range or does this depend on the shooter's eye too ?