I have recently started looking into foveal vision and how it relates to screen space / UX. I dig up a lot of interesting information but I can't seem to find any information how foveal vision works for both eyes. Almost every paper / book / site I have read references to the foveal vision of an eye but it doesn't take into consideration that humans have two eyes.

People tend to use the following image as a reference, it is linked on wikipedia and it comes from some German book (unfortunately I can't speak German).

enter image description here

As awesome as this image is, it only relates to the left eye. Does anyone know any information that deals with both eyes? Such as the shape of the foveal vision? How do the eyes add up? etc.

The literally only thing I have been able to find so far are these images from simplifyinginterfaces.com but these seem more like promo pictures rather than a serious research.

enter image description here

Any ideas where should I look?

  • I'm not an expert but I would have thought that given both eyes are (usually) focussed on the same place I would have thought that the fovea occupies the same location (relatively speaking) on the image for each eye. – ChrisF Jun 13 '12 at 11:37

As Chris suggested, the two eyes work together. Remember, vision is not a property of one eye; the vision is a joint effort between both eyes, the nerves and the brain. Since the eyes are generally focused in one area, they work together and the brain joins the two images into one, like a panorama setting on a camera. In that way, you are basically designing for one eye.

A good book on the topic is 'Designing with the Mind in Mind'. It is about how psychology (and perception) relates to UX design. It has a section on vision and offers specific design ideas to accommodate it.

Unless you are designing specifically for people with vision deficits and need to know how to compensate for them, the amount of information covered by this book will probably suffice.

  • Thanks for the answers Chris and chantastique. I agree with you and I came to the same conclusion but I would like to see more scientific approach to this. 'Designing with the Mind in Mind' is on my TO-READ list, I hope it will help a bit. – Kraken Jun 16 '12 at 11:40

Regarding the shape, I found amazing infographics done by Wertheim in 1894. The graphics also contains the visual acuity values stepped by 5 degrees.

Wertheim 1894

I'm still looking for the problem with two eyes, I believe using both eyes changes the visual acuity values but I cannot find any proof.

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