If you load into your world and see pitch-black darkness instead of ores, you are experiencing a lighting engine limitation. In Minecraft 1.8.8, invisible blocks do not let ambient surface light pass through them naturally.
An Xray texture pack for Minecraft 1.8.8 modifies in-game textures so most blocks become nearly invisible while ores and selected blocks remain visible, making resource locating much faster. This article explains what Xray packs do, legal/ethical considerations, how they work, how to install one for 1.8.8, configuration tips, performance notes, and safe alternatives. xray texture pack 188 work
If you see through the map but cannot see ores, the server is using a anti-xray plugin. Performance: If you load into your world and see
Set to Fast . This reduces the rendering overhead caused by transparent block faces. This article explains what Xray packs do, legal/ethical
Are you using any other mods like or Labymod alongside OptiFine?
These plugins do not look at your game files; instead, they alter the packets sent from the server to your computer. They turn all hidden blocks into random ores until you directly mine next to them. If you join a server and see a confusing cluster of random diamond, emerald, and gold blocks that disappear when you get close, the server has successfully blocked your texture pack.