You can see through blocks

Can not reproduce. Can you provide more details about your system?

Which potion effect are you under?

Regen and resistance and speed it think

-Scott

We need some more info, which video settings did you select ingame? simple/advanced etc?

Can you do this consistently? is it only on this map/location? Could you perhaps upload the map to a public location so we could check if that is the case?

It seems like a transparency flag of sorts is still turned on. No idea what causes that.

I use a custom texture pack that changes the side of grass and it works on any map without potion effects. Fancy and fast graphics don't change it. Only view distance. I use fullscreen on a 64 bit Mac. Also, I was using a multiplayer server.

-Scott

I use my texture pack, but no mods

The problem is with your texture pack; the terrain.png has a maximum opacity of 92%, so it's no real surprise you can see through everything. Not sure why this only happens with tiny view distance, possibly some optimizations are disabled there that normally hide surfaces that should be invisible anyway.

I don't get it, this is an issue with your texture pack having opacity, not minecraft...

Resolve as invalid since no minecraft issue

Note that you can see the red text THROUGH the textures, making this an issue with the texture pack being used, not Minecraft.