In Minecraft, the contours of the blocks are so weird, what settings do I have to change to get this done? PS: I have Optifine?

Picture is in my answer

I ask for help!

Anti aliasing or so if the MC has.
Otherwise resolution

Optifine install and under quality the anti-aliasing to 4 or better

Put anti-aliasing and antisotropic filtering in place, but you'll need OptiFine for that.