Eye of Cthulu isn't spawning!?

[Future]

I have 220 health, and 18 defense, i have 6 npc's in my world , and i haven't fought the Eye of Cthulu before yet he won't appear in my world! Why?? I have heard these are the requirements for fighting the Eye of Cthulu:

1. One player must have at least 200 health, and 10 defense (One player in the case of a multiplayer world)
2.3 NPC's must be living in houses in the player's world.
3.The Eye of Cthulhu has not yet been defeated in the current world.

If you have any questions or help for me, Please respond in this discussion thread!

[Beanstalk]

It's random. The best way to fight him is to make his summoning item.

[Future]

I have the summoning item but i don't want to use it because i want to fight him 2 times (Him Spawning naturally, then i use the spawn item to fight him)

[VagueCryptid]

You can make hundreds of summoning items if you want, just needs 6 lenses each, craft it at a Demon or Crimson Altar. If you have 18 defense, you might as well go and beat Skeletron and move on with the game.

[so true bestie]

You can make the spawner with just like 6 lens, so just make another one.

[Ember]

It can take multiple nights for him to appear, you'll just have to wait until he does. Best of luck with the dual fight though.

[Future]

Where would i make the Eye of Cthulu spawn item at a regular work bench or anvil?

[Randy]

You make it at a demon altar.

[Future]

oh okay. Thanks guys

[Future]

Finally guys i was just randomly playing Terraira and it was night time and the "you feel an evil presence watching you" message finally came up. Man thanks for all of your tips i'm definitely going to fight the Eye of Cthulu twice then i'm going to move on to exploring and preparing for the Brain of Cthulu. (I hate my world for having the Crimson biome because I prefer the Corruption biome)