CSCIE 236 – Homework 1, ÒEye VisualizationsÓ

Russell Lowke Feb. 16th 2005

 

            The human eye is very complex and diagrammatic visualizations are often used in an attempt to explore and reveal its intricacies.  In particular, the eye has a Blind spot  in its field of vision which lies on the point of the retina where the Optic nerve leads back into the brain.  Conversely, close to the optic nerve, there is a small and highly sensitive part of the retina responsible for detailed vision known as the Macula, the center of which is referred to as the Fovea.

 

 

GOOD VISULIZATION:

 

Source:  A.D.A.M. (Animated Dissection of Anatomy for Medicine) a Multimedia CD-ROM on human anatomy, first published in 1994.

< http://www.adam.com/index.html >

< http://whyfiles.org/163amd_eye/images/eyeball.jpg >

 

            3D visualization is very effective and desirable method of depicting the human eye, although hard to do accurately. Above is a very good 3D visualization of the eye from the multimedia CD-ROM A.D.A.M.  It is clearly labeled and, by use of a cut away, exposes the intricacies of the eye in very appropriate color.  It is worth noting that human retina is in fact black and that here red is used instead so to make visible the retinal veins.  All proportions of the eye are immediately clear and we are presented with a sensory representation that is easy and quick to understand.

            Although accurate, what is not immediately apparent is that the visual axis (focus) from the lens falls onto the macula and the optic axis, which passes through the centre of the iris, falls half way between the optic nerve and the macula. Interestingly, this fact is better shown in a more arbitrary 2D representation, such as one found at 

< http://remort.wz.cz/retina/II/images/DRAWEYE.png > where the positions of the macula and the optic nerve can be seen in relation to the focus of the eye.

 

 

BAD VISULIZATION:

Source:  Colin Ware, Information Visualization, (San Francisco, Morgan Kaufmann, 2004): 39. Fig 2.9.

 

 

            This visualization from the required class text by Colin Ware fails because it attempts to mix both 3D and 2D paradigms--creating a highly misleading visualization.  We see a very novel but confusing representation of the Lens, which is shown in 2D and yet is seen also in a 3D context.   The Cornea is very definitely drawn in 2D conflicting with the Iris, which is in 3D.  I am not sure from which perspective I should use to identify information.  The arbitrary arrows used to depict the eye muscles are also confusing, as arrows have already been used for labels. Worst of all, due to the conflicting paradigms this representation appears to place the Blind spot  (Optic nerve) on the far side of the eye and the nearby Fovea (Macula) as being very widely distanced from it.