Concepts pertaining to ophthalmology have lots of theoretical frameworks. Neophyte residents and novice surgeons may have to mentally visualize these concepts during the initial days of training. Only a powerful cognitive tool such as a three-dimensional (3D) eyeball model. with real-time TrueColor confocal images (and not animated images or models). https://www.roneverhart.com/9-Inch-Modern-Entry-Door-Lockset-Emtek-8114/