MonoBehaviour.OnMouseDown()

Description

OnMouseDown is called when the user has pressed the mouse button while over the GUIElement or Collider.

This event is sent to all scripts of the Collider or GUIElement.

using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement;

public class ExampleClass : MonoBehaviour
{
    void OnMouseDown()
    {
        // load a new scene
        SceneManager.LoadScene("OtherSceneName");
    }
}

This function is not called on objects that belong to Ignore Raycast layer.

This function is called on Colliders marked as Trigger if and only if Physics.queriesHitTriggers is true.

OnMouseDown can be a co-routine.