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.
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.
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.