EyeMeasure is a mobile application (iPad recommended) to assist in measuring interpupillary distance (IPD) or the distance between centres of the pupils. It uses the camera on your iPad or iPhone to capture an image of your face and then provides a measurement of the distance between the pupils of your eyes. Not only are these apps useful for fitting eyeglasses but also for adjusting virtual reality (VR) headset settings to ensure an optimal viewing experience (and less nausea or headaches). By accurately measuring IPD, you can align your VR headset’s optics correctly with your eyes, for better comfort and a more immersive experience.
EyeMeasure (iOS only) is free on App Store, GlassesOn/Pupils & Lenses is the free Android alternative that does the same thing, on GooglePlay.