How do I check if the mouse is over a VISIBLE vertex?

Hi, how do I check if the mouse is over a visible mesh vertex in the scene view. I can get the vertex under the mouse using the following code:

 using UnityEditor;
 using UnityEngine;
 
 [CustomEditor(typeof(Test))]
 public class TestEditor : Editor
 {
     private MeshFilter meshFilter = null;
     private void OnSceneGUI()
     {
         if (meshFilter == null)
         {
             meshFilter = ((Test)target).GetComponent<MeshFilter>();
         }
         for (int a = 0; a < meshFilter.sharedMesh.vertices.Length; a++)
         {
             Vector3 screenPoint = SceneView.currentDrawingSceneView.camera.WorldToScreenPoint(meshFilter.sharedMesh.vertices[a]);
             screenPoint.y = SceneView.currentDrawingSceneView.camera.pixelHeight - screenPoint.y;
             if (Event.current.mousePosition.x >= screenPoint.x - 5 && Event.current.mousePosition.x < screenPoint.x + 5 && Event.current.mousePosition.y >= screenPoint.y - 5 && Event.current.mousePosition.y < screenPoint.y + 5)
             {
                 //THE MOUSE IS OVER THIS VERTEX.
             }
         }
     }
 }

The above code only checks if the mouse is over the vertex, not if there is a triangle in the way. How do I check if there is a triangle in the way (raycasting?). Thanks :D