Hey Smudge, congrats on the lds!

To answer your questions - you usually don't need to open your eyes during a lucid dream, technically you don't have any eyes so just try to see through your eyelids and recognize what's around you.

Regarding the second question and perhaps also relating to your second experience - maybe it was just a matter of the dream forming more fully, rather than an actual vision problem. So, if this is the case, I would suggest to just wait out for the picture to fully form and in the meantime try to focus on anything you see - any lines and curves that you see and how they form objects. The more you keep your focus on these, the more the rest of the picture should show up.