Mother cat is acting strange, one of the kittens also acting strange?

As Katy had said, cats are not always the best moms. I have raise a batch of kittens before, and had to supplement another and it can be done. You can feed them fully by yourself or track down lily and just supplement them. You can go to any pet store or your vets and get a kitten bottle and kitten milk replacer (cow milk does not have enough nutrients to feed a kitten). Cut a hole in the nipple that comes with the bottle, not too big an x is a good indicator but not the whhole circumference of the nipple (not edge to edge about half way) the clerk at the pet store could probably show you. If you want to step in and be mom, bring the kittens inside, get a crate for them, and feed them, it will take some time for them to cathc on to the artificial nipple, but if they are really hungry it should not take long. If you want to supplement them just make up the milk and take it out to them, make sure they have a nice bed in as warm and dry a spot as you can find, especially since mom might not be so interested in them, but she could come back and decide she likes them. Its up to you and how much time you have, you have to feed them every two or every few hours anyways while young, but you want to make sure they are getting enough, if they drink a lot from the bottle mom is not given them much or any. Hopefully you can get some food into them and they will start doing well! Good luck!!

Cats do not always raise their young very well. What most mother cats will do after they have kittens is care for them until they are a little bit older, then leave to find another mate and have more kittens. So, in short, they don't usually stick around very long. House cats don't do this as much as wild ones, I believe, or barn ones. It is a natural, but sad, thing, and in my opinion the best thing you can do is feed the kittens yourself. Get a little bottle or leave them a little bowl of milk until they're old enough to hunt and supply food for themselves.

The kitten might have walked into a wall because of hunger, yes. There is the chance that he has eyesight problems, especially is he was born a couple days ago and his sight hasn't developed completely. Kittens are born blind and it takes them some time to see properly. Otherwise, it might have been hunger...

The kittens sound like they are roughly a month old. Since they survived this far without human intervention for a while at least she was feeding them and attending to them properly. As they get larger and older it is not uncommon for the mother to have issues both feeding the kittens and maintaining her own weight and health. The kittens are old enough at this point to eat canned kitten food in a dish. If you place the kittens near it, they will likely eat. You also could get some KMR (kitten replacement milk) for them to drink for nutrition. As far as the eyesight of the kitten who bumped into the wall, it is impossible to say based on the one incident whether the eyesight of the kitten is impaired. If the kitten plays normally with the other kittens then most likely the eyesight is not bad.