The How iSee app was developed to simulate symptoms and progression of an inherited retinal disease known as Choroideremia (CHM). It uses real-times images from the phone’s camera which can be increased in severity by using the headset input or tapping the screen. This app was designed for use with VR headsets portable for a smartphone(excluding Gear VR), preferably with a camera hole on the right side of the headset for a screen-right orientation.