Using raycast to check if object is on/off screen

Hi, I just can’t make script that will check if camera is looking at the object. Script below only check if camera is directly looking at object, but I need to check if object is on camera(not behind).

var hit: RaycastHit;

if(Physics.Raycast(cam.transform.position,cam.transform.forward,hit, distance))


        if (hit.collider.gameObject.tag == "Player")

            // Do something

Use this: Unity - Scripting API: Renderer.isVisible