How do I limit the angle of transform.lookat function

I have searched on google and the unity answers site and still haven't found a solution that works yet. I would like the head of my enemy character to only move -+90 degrees. So like a normal person. Now it just rotates 360 degrees and it is not natural. Is there any simple and safe way to do this. This is what I have already: public Transform head; //.... underneath is in an update function Vector3 playerPos = new Vector3(player.position.x, head.position.y, player.position.z); head.LookAt(playerPos); If anyone could help that would be great thank you