Traumatic optic neuropathy (TON) refers to an acute injury of the optic nerve secondary to trauma. The optic nerve axons may be damaged either directly or indirectly and the visual loss may be partial or complete.
In Minecraft, emerald ore is very hard to find and is found in small deposits in the Extreme Hills biome. You can usually find emerald ore between 13 and 31 blocks below the ground and close to lava. So if you see a pool of lava in the Extreme Hills biome, that is a great place to start mining downward.
Mycelium is a block added in Minecraft the same time as the introduction of the Mushroom Biomes in Minecraft 1.9pre1. Mycelium can only be found and only can be found in Mushroom Biomes. Mycelium resembles dirt in that it can be broken with a shovel and it without a 'Silk Touch' enchanted tool it only drops dirt when broken. Mycelium also lets off a small particle effect the same as Bedrock.