This device is meant to be used by optometry students, optometrists, ophthalmology residents, or ophthalmologists to practice indirect ophthalmoscopy skills and is not intended for diagnosis of ocular pathologies. Requirements: 20 diopter indirect ophthalmoscopy lens (purchased separately), dental mirror approximately 1 inch in diameter (available at low cost online) or similar mirror. The device clips onto the top of the user's iPhone over the flash LED. The flash points into the device toward the end with the beveled arch. A dental mirror is inserted under the flap as far upward as possible with the silvered side facing the flash LED and held in place with tension or glue. To use, activate your iPhone flashlight and turn the phone so you are facing the back of the phone. Slide the device to the left or right along the top of the iPhone to adjust the square lightbeam until it is straight ahead. Look through the square eyehole under the beveled arch and place the lightbeam over the patient's pupil. You should see the red reflex from the retina. Interposing a 20D lens will allow a magnified view of the fundus. Utilizing a 3rd party iPhone application which allows dimming of the LED may facilitate a better view in an undilated pupil.