The top 6 are all fairly equal in their ranks, and all submissions were well done. Number 3 does a great job of highlighting the "MD" portion of our name, that's important. Numbers 12 and 13 are very nice designs and really push forward the medical nature of what we do, also excellent. Numbers 6, 4, and 7 are similar to number 3 in theme
For numbers 3 and 6,4,7, I would suggest trying to modify the 'curves/eye' portion to maybe simplify it, make it stronger, possibly thicker, maybe a little flashier to highlight the very advanced technology of what we do, while still maintaining the MD emphasis.
For numbers 12 and 13, possibly modify the logo to make both the eye and cross more subtle...you have really pushed across the medical nature of what we do, and that's excellent, but trying to meld an eye and a cross is really tough and can create a conflicting and confusing logo. Please try to build upon these comments to create a smoother, perhaps more subtle meld of the eye and cross, and please also insert a space between the MD and EyeCare.
Numbers 1 and 2 are nice attempts to create a logo blending the oval of the eye with a cross. As noted above, it is a tough mission to blend the two, and I encourage more attempts to bring the two together in a more seamless and natural way.