diff --git a/3-mid/opengl/source/lean/renderer/opengl-renderer-lean.adb b/3-mid/opengl/source/lean/renderer/opengl-renderer-lean.adb
index 80428af..1b5524d 100644
--- a/3-mid/opengl/source/lean/renderer/opengl-renderer-lean.adb
+++ b/3-mid/opengl/source/lean/renderer/opengl-renderer-lean.adb
@@ -1029,6 +1029,13 @@ is
       end rid;
 
 
+      function Exists (Id : in openGL.light.Id_t) return Boolean
+      is
+      begin
+         return the_Lights.Contains (Id);
+      end Exists;
+
+
       function get (Id : in openGL.Light.Id_t) return openGL.Light.item
       is
       begin
@@ -1087,6 +1094,13 @@ is
    end rid;
 
 
+   function Exists (Self : in out Item;   Id : in openGL.light.Id_t) return Boolean
+   is
+   begin
+      return Self.Lights.Exists (Id);
+   end;
+
+
    function Light (Self : in out Item;   Id : in openGL.light.Id_t) return openGL.Light.item
    is
    begin
diff --git a/3-mid/opengl/source/lean/renderer/opengl-renderer-lean.ads b/3-mid/opengl/source/lean/renderer/opengl-renderer-lean.ads
index 697a661..82fd67f 100644
--- a/3-mid/opengl/source/lean/renderer/opengl-renderer-lean.ads
+++ b/3-mid/opengl/source/lean/renderer/opengl-renderer-lean.ads
@@ -46,8 +46,10 @@ is
    procedure add       (Self : in out Item;   the_Light : in Light.item);
    procedure set       (Self : in out Item;   the_Light : in Light.item);
    procedure rid       (Self : in out Item;   the_Light : in Light.item);
-   function  Light     (Self : in out Item;   Id        : in light.Id_t) return openGL.Light.item;
-   function  fetch     (Self : in out Item)                              return openGL.Light.items;
+
+   function  Exists    (Self : in out Item;   Id : in light.Id_t) return Boolean;
+   function  Light     (Self : in out Item;   Id : in light.Id_t) return openGL.Light.item;
+   function  fetch     (Self : in out Item)                       return openGL.Light.items;
 
    type context_Setter  is access procedure;
    type context_Clearer is access procedure;
@@ -272,7 +274,8 @@ private
       procedure set (Light : in openGL.Light.item);
       procedure rid (Light : in openGL.Light.item);
 
-      function  get (Id    : in openGL.light.Id_t) return openGL.Light.item;
+      function  Exists (Id : in openGL.light.Id_t) return Boolean;
+      function  get    (Id : in openGL.light.Id_t) return openGL.Light.item;
       function  fetch                              return openGL.Light.items;
    private
       the_Lights : id_Map_of_light;