Preview
SensAble Vision
Android app, web app and Meta Quest 3
Uses the camera to simulate in real time how people with visual impairments see the world. Press and hold to see normal vision.
- Android, browser and Quest 3 – in the headset, each eye separately
- Catalogue with severity levels, combinations and assistive aids
- Hands-on tasks and a WCAG contrast check
SensAble Vision for Android
Installation and what’s new
- Download: on your phone with the button, or on a computer via the QR code.
- Open: tap the file. If Android asks, turn on “Allow from this source”.
- Install – tap it. When a new version is available, the app tells you at start-up.
New in 1.0.2: Major overhaul: more realistic blur and visual fields, combinations in any order, new catalogue with filters and preview images, assistive aids, hands-on tasks, contrast check for your own images, experimental gaze control – and automatic updates from now on.
Scientific basis and limits
The app calculates with real camera measurements: focal length and sensor size give the visual angle per pixel, exposure gives the pupil size (after Watson & Yellott 2012). This makes field losses and blur correct in degrees of visual angle – each simulation with its own shaders, in clinical severity levels and, if desired, for each eye separately.
- Published models: colour vision after Machado et al. (2009), straylight in cataract after van den Berg (1995), glaucoma along the nerve fibres after Hood & Kardon (2007) – explained for every condition in the app, with sources.
- 57 conditions, freely combinable: the result does not depend on the order – a test checks this for all 1,596 pairs.
- Limits: A simulation shows a moment, not life with a visual impairment, and does not replace an eye examination.
The preview above, limits in detail and sources
The preview above is heavily simplified: a photo with filters in the browser, without camera, measurements or severity levels. In the app, the five examples are based on these models:
- Cataract
- Straylight as a broad veil (van den Berg 1995), yellowish lens (Pokorny et al. 1987), patchy clouding and glare halos.
- Macular degeneration
- Central scotoma with an irregular edge, distortion and delayed dark adaptation (Owsley et al. 2001); the experience based on reports from people affected (Taylor et al. 2018).
- Glaucoma
- Typical progression from arcuate scotoma to a residual island following nerve-fibre anatomy (Hood & Kardon 2007); losses appear blurred rather than black (Crabb et al. 2013).
- Diabetic retinopathy
- Patchy losses that increase in number with severity, loss of contrast and a slight blue–yellow deficiency.
- Red–green colour blindness
- Physiological model by Machado et al. (2009) in linear colour space; the preview uses its matrix for deuteranopia.
Limits in detail: the simulation shows what an eye sees – not how the brain adapts over years. Phones and the Quest 3 have no eye tracking: losses move with the image, and you have to look at the fixation point (gaze control via the front camera is experimental). The Quest 3 shows about 25 pixels per degree, so “normal vision” there corresponds to a visual acuity of about 0.5 at most.
Sources (selection)
- Crabb DP, Smith ND, Glen FC, Burton R, Garway-Heath DF (2013): How does glaucoma look? Patient perception of visual field loss. Ophthalmology 120(6), 1120–1126.
- Hood DC, Kardon RH (2007): A framework for comparing structural and functional measures of glaucomatous damage. Progress in Retinal and Eye Research 26(6), 688–710.
- Hu CX, Zangalli C, Hsieh M et al. (2014): What do patients with glaucoma see? Visual symptoms reported by patients with glaucoma. American Journal of the Medical Sciences 348(5), 403–409.
- Machado GM, Oliveira MM, Fernandes LAF (2009): A physiologically-based model for simulation of color vision deficiency. IEEE Transactions on Visualization and Computer Graphics 15(6), 1291–1298.
- Owsley C, Jackson GR, White M, Feist R, Edwards D (2001): Delays in rod-mediated dark adaptation in early age-related maculopathy. Ophthalmology 108(7), 1196–1202.
- Pokorny J, Smith VC, Lutze M (1987): Aging of the human lens. Applied Optics 26(8), 1437–1440.
- Taylor DJ, Edwards LA, Binns AM, Crabb DP (2018): Seeing it differently: self-reported description of vision loss in dry age-related macular degeneration. Ophthalmic and Physiological Optics 38(1), 98–105.
- van den Berg TJTP (1995): Analysis of intraocular straylight, especially in relation to age. Optometry and Vision Science 72(2), 52–59.
- Watson AB, Yellott JI (2012): A unified formula for light-adapted pupil size. Journal of Vision 12(10), 12.