This makes so much sense

In Israel if you sign up as a transplant donor you and your family move up the waiting list for any transplant.

I would go even farther: You should only be eligible for an organ transplant if you have agreed to donate your organs before the illness that led you to need the organ was diagnosed. If you'll only give up your eyes, you can only get eyes. Would lead to much higher donation rates. I'd probably sign my card because for the first time I'd get something for the signature other than a prim, self righteous feeling.