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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.


   Myopia (Nearsightedness)
   Hyperopia (Farsightedness)


Refractive Errors

Refractive errors are normal optical properties in the eye that lead to ineffective 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 optics of the eye and refractive error, go to Optics and Refractive Error.

Normal, Myopic and Hyperopic Views

In the left normal view of the Italian Gardens at Maymont Park, Richmond VA, both the near and the far distance
are clear. In the middle nearsighted (myopia) view, the near is clear but the midrange and distance become
progressively more blurred. In the right farsighted (hyperopia) view, both the distance and the near are blurred,
but the distance is relatively clear compared to the near.

Normal and Astigmatism Views


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 these images of Capitol Square in Richmond, Virginia, the astigmatism is oriented vertically and this results in the selective blurring of vertical lines as shown in the view on the right.

Normal and Nuclear Sclerotic Cataract Views



The left view is a clear image of the Virginia Biotechnology Center in Richmond, Virginia. The view on the right 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.

Normal and Posterior Subcapsular Cataract Views



The clear view on the left is of an infamous decorated house on Asbury Ct. in Richmond, Virginia. The view on the right represents the blur caused by a "posterior subcapsular" type of cataract that 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 on the Symptoms and Disorders Page.


Normal and Glaucoma Views




The A view on the left is a normal view of a street with no loss of peripheral vision. The B view on the right 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 in the C view below and left.





The D view on the right shows a severe loss of visual field in advanced glaucoma in a 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 creating an especially severe loss of vision.


For more information, go to Glaucoma on the Symptoms and Disorders Page.


Normal and Macular Degeneration Views




The clear view of this building on the left is normal without macular degeneration. The middle view demonstrates distortion typical of early neovascular ("wet") macular degeneration, with distortion of the retina. Although distorted, the lettering is still readable. With the view on the right with a more severe case of "wet" macular degeneration, the vision is distorted and also lost centrally. Other conditions causing swelling of the central retina may cause this visual distortion, such as cystoid macular edema, central serous choroidopathy, diabetic macular edema and others.



For more information, go to Macular Degeneration on the Symptoms and Disorders Page.



Normal and Retinal Detachment Views


In the upper view is a normal view of the Richmond skyline. In the the lower view with an area of a retinal detachment, vision is lost. At the margin of the detachment, the vision may be distorted.




Normal and Vitreous Hemorrhage Views





The view on the left is of a normal view of a lake at Lewis Ginter Botanical Gardens in Richmond, Virginia. In the view on the right, there are strands of blood creating a veil over the vision. This represents a minor hemorrhage into the vitreous body of the eye. Causes could include diabetic retinopathy, retinal tears, vitreous detachment, sickle cell retinopathy and others.




Double Vision



You can appreciate the 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 oculomotor nerves controlling eye movement or with thyroid related orbital problems.



Ophthalmic Migraine



These are two depictions of the visual phenomena (aura) that can be experienced 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. Or, it may start temporally and move toward the center of vision. There is a scotoma, or a blind 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. The following link is an excellent YouTube video simulation AURA of an ocular migraine. Click the back arrow to return here.


Normal and Colorblind View



These images demonstrate how individuals with normal color vision and abnormal color vision 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 image. With total color blindness, there is no number or pattern visible, as is shown on the right. This is rare.