You might already have a lot of Monster Eyes

If you already have any other eyes such as Nekker Eyes or Fiends Eyes then you are in luck! You can dismantle all these eyes to make Monster Eyes. To dismantle them, go to any blacksmith or armorsmith and choose the ‘Dismantle’ option in the crafting menu.

Where to find Monster Eyes

If you want to craft items in Witcher 3 then you will find that a lot of them require Monster Eyes (especially the best items currently available). The easiest way to obtain these eyes is by using the “dismantle” crafting option on various different eyes you might find. Pretty much any monster you kill will drop it’s own type of eye, such as a Drowner Eye. You can dismantle these into Monster Eyes. There are several places you can find a lot of monsters that you can quickly kill for a lot of eyes.

What monsters to kill for Monster Eyes

Nekkers

One of the quickest ways to obtain Monster Eyes is by killing packs of Nekkers. Nekkers are weak creatures that attempt to swarm and overwhelm you. Once you reach level 20+ then you should no longer have any problems killing Nekker swarms of any size. You can find a lot of Nekkers at the location shown below in Novigrad.

Nekker Nests - Monster Eyes

All the nearby monster nests have a lot of Nekkers. Kill them, meditate and kill them again. Dismantle Nekker Eyes to get Monster Eyes.

If you have already killed these nests then I recommend trying to find Drowners (or hunting for other Nekker Nests)

Drowners

Drowners are one of the first types of monster you will encounter. As the name suggests, they hang around near water and try to drown you. Again, Igni is very strong against them. Drowners often come in sizeable packs and have a fairly good drop rate for their eyes (which dismantle into Monster Eyes). Drowners are very common creatures, just wander around areas by water and you are bound to find some. There are also groups of them to be found at Crookback Bog on the map below.

Lots of drowners here

I hope this helps you find Monster Eyes. Good luck crafting!