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Simulations of Eye Disorders
This page shows simulations of
visual symptoms caused by a variety of eye disorders, from simple refractive
error, to localized eye problems, to neurological problems. Please note
that these simulations are generally based on the author's interpretation of
symptoms described by patients, as well as on knowledge of the disease processes
themselves. There may be wide variations in an individual's own visual
experiences with any disease process.
Read this important information
before proceeding further:
These sections are not intended to replace the professional examination and
diagnosis by a physician, and they are presented here purely for informational purposes.
All possible diagnoses and treatment options are not covered, and the information
discussed should not be taken as a recommendation to self-diagnose and self-treat a
condition. A misdiagnosed or improperly treated eye condition can result in a permanent
loss of vision, or a permanent loss of function of the eye or visual system. In the case
of any eye problem, seek medical attention promptly. This can include emergency room
treatment, as well as treatment by a medical physician or eyecare provider.
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Topics Include:
For eye anatomy explanations, go to
ANATOMY
Refractive errors are optical abnormalities in the eye that lead to
improper focusing of images onto the retina. Refractive errors are
generally correctable by glasses, contact lenses, or refractive surgery.
Thus, blurred vision due to refractive error alone does not cause an
untreatable loss of vision (the eye is otherwise healthy). For more
information on the optics of the eye and refractive error, go to
Optics and Refractive Error.
Refractive Error:
Normal Image
This is a normal image of the Italian Gardens at Maymont Park, Richmond
VA. Both the foreground and the far distance are clear.
Refractive Error:
Myopia
In this myopic (nearsighted view) of the gardens at Maymont Park, the
foreground is clear but the midrange and distance become progressively
blurrier.
Refractive Error:
Farsightedness
Both distance and near are blurred, but the distance is relatively
clear compared to the foreground.
Refractive Error:
Astigmatism (Uncorrected View)
Astigmatism is usually caused by the cornea not being perfectly round
in all directions, leading to different parts of an image being blurred,
depending upon the orientation of the astigmatism. In this image of
Capitol Square in Richmond, Virginia, the astigmatism is oriented
vertically, thus there is selective blurring of vertical lines as shown in
the photo.
Refractive Error:
Astigmatism (Corrected, or Normal View)
Clear image of Capitol Square.
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Eye Disorders:
Cataract, Normal View
Clear image of the Virginia Biotechnology Center in Richmond, Virginia.
Eye Disorders:
Nuclear Sclerotic Cataract
This image represents the view through a "nuclear sclerotic"
type of cataract. Note that in addition to the image being blurred, it is
also dim and less colorful than the normal view. The color blue is
especially obscured by this common type of cataract.
Eye Disorders:
Posterior Subcapsular Cataract (Normal View)
An infamous decorated house on Asbury Ct. in Richmond, Virginia.
Eye Disorders:
Posterior Subcapsular Cataract (Cataract View)
The "posterior subcapsular" type of cataract often affects
younger individuals, and those with diabetes or on steroids. There may be
severe glare with this type of cataract, with halos and starbursts being
visible from point sources of light.
For more information, go to
Cataract.
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Eye Disorders:
Glaucoma, normal view.
This is a normal view of a street with no loss of peripheral vision.
This demonstrates a common type of blind spot found early in glaucoma.
If the eye is fixating down the road, the pedestrian on the right
partially disappears. There is a reduction of sensitivity in the
peripheral vision in the area shown within the dotted lines below:
Eye Disorders:
Glaucoma, severe loss of vision
This shows a severe loss of visual field in advanced glaucoma, left
eye. Only an island of central vision remains, with some field of vision
toward the outside left as well. The blind spot cuts horizontally through
the center of vision, an especially severe loss of vision.
For more information, go to
Glaucoma.
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Eye Disorders:
Age-Related Macular Degeneration
Normal View
Clear image of a building in this case with no macular degeneration.
Eye Disorders:
Macular Degeneration, early "wet" type
This demonstrates distortion typical of early neovascular
("wet") macular degeneration, with distortion of the retina.
Although distorted, the lettering is still readable.
(Note: Other conditions causing swelling of the central retina may
cause this visual distortion, such as cystoid macular edema, central
serous choroidopathy, diabetic macular edema, among others.)
Eye Disorders:
Macular Degeneration, more severe.
In this more severe case of "wet" macular degeneration, the
vision is distorted and also lost centrally.
For more information, go to
Macular Degeneration.
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Eye Disorders:
Retinal Detachment, normal view.
Normal view of Richmond skyline.
Eye Disorders:
Retinal detachment
In the area of a retinal detachment, vision is lost. At the margin of
the detachment, the vision may be distorted.
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Eye Disorders:
Vitreous Hemorrhage
Eye with strands of blood creating a veil over the vision. This
represents a minor hemorrhage into the vitreous body of the eye. Sources
could include diabetic retinopathy, retinal tears, vitreous detachment,
and sickle cell retinopathy, among others.
Eye Disorders:
Vitreous hemorrhage, normal view.
Normal view of a lake at Lewis Ginter Botanical Gardens in Richmond,
Virginia.
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Eye Disorders:
Double Vision
Double vision looking down a road leading into Shockoe Slip, in
downtown Richmond. In this case, the double vision is oriented
horizontally (side by side). This could occur with dysfunction of certain
nerves controlling eye movement, or with thyroid related orbital problems.
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Eye Disorders:
Ophthalmic Migraine
Click
for a Larger Image
This is a depiction of the visual phenomenon experienced by
many before a migraine headache. The area of jagged, zigzag lights are constantly
in motion, flashing over a 15 to 30 minute time frame. The area
involved often starts small near the center of the vision, then moves
outward slowly. There is a scotoma, or a blink spot, in the area of the
disturbance, which is seen in the same field of vision of both eyes. A migraine headache
may, or may not, follow this aura.
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Eye Disorders:
Color blindness
These images demonstrate how individuals with normal color vision, and
abnormal color vision, might view this color vision test. Those with
normal vision would see the number "3" as shown on the left.
With mild color blindness (as is present in about 8% of males), the number
may be misread as a "5", as shown in the middle. With total
color blindness, no number or pattern is visible, as shown on the right
(rare).
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