Your Window Into Eye Disease

The EyeSimulator shows how common eye diseases like glaucoma, diabetic retinopathy, age-related macular degeneration and cataracts may affect vision.

How to use the EyeSimulator

  1. Select an image from the ones displayed below. The image will appear in the larger box pane.
  2. Pick one eye condition from the list, below the small pictures.
  3. Move the slider located below the picture to see the progression of the eye disease.
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Age-related macular degeneration

No visual symptoms are present at this stage.

As symptoms of macular degeneration begin to become apparent, individuals will start to experience a loss of vision in the centre of their sightline, which can sometimes look like a soft grey-black mass that can be somewhat translucent in the beginning.

At the mid-stages of macular degeneration, the mass/blind spot obstructing central vision can become more opaque and begin to expand. There may also be a slight haziness surrounding the blind spot and light, translucent shapes may begin to form throughout the visual field.

As macular degeneration progresses, the blind spot in the centre of the sightline may become larger and more opaque. The translucent shapes present throughout the visual field may also grow slightly and become more opaque.

In the later stages of macular degeneration, the central blind spot grows and individuals may experience great difficulty executing everyday tasks like reading or walking. There may also be blurring and faint obstructions in other areas of the visual field.

Age-related macular degeneration (AMD) is the leading cause of vision loss in Canadians 50 years and older, causing damage to the macula (the central part of the retina) and can result in a loss of central vision. There are two forms of AMD: dry and wet. 90% of people with AMD have the dry form, which can convert to the wet form. Wet AMD can quickly lead to vision loss if not treated right away. Although it isn’t known what causes AMD or why it progresses to the later stages, treatments are available to slow down the degenerative process.

Diabetic Retinopathy

No visual symptoms are present at this stage.

During the early stages of diabetic retinopathy, dark, irregularly shaped obstructions begin to pepper the field of vision. There may also be some overall darkening in the field of vision, as though a light has been dimmed.

With mid-level diabetic retinopathy, the dark obstructions throughout the field of sight may grow and spread, making it very difficult for the individual to navigate their surroundings. There may be an overall dimming effect in the remaining vision.

Very little clear vision will remain at the final stages of diabetic retinopathy, as the dark obstructions spread and almost entirely consume usable vision.

At this point, the person may have very little, if any, usable vision. The dark obstructions will likely have spread to almost entirely blanket the visual field. Any vision that remains will likely be blurry and dim.

Many people living with diabetes have some form of diabetic retinopathy, a condition that occurs when elevated glucose levels in the blood cause blood vessels in the eye to swell and leak in the retina. Often there are no symptoms in the early stages and vision is not affected. Without treatment, diabetic retinopathy can advance to uncorrectable vision loss – often appearing as blurred or patchy vision – or even blindness, usually in both eyes. With routine eye examinations, diabetic retinopathy can be detected and treated.


No visual symptoms are present at this stage.

In the early stages of cataracts, a light cloudiness can begin to appear, often in the centre of the sightline, but some patches of sight may still remain clear.

At the mid-stage of cataracts, the cloudiness becomes more opaque and grows to cover a larger area of the visual field. Small translucent-white dots may also become visible.

As the cataracts progress, the cloudiness and dotting effect continue to spread and become thicker. The effect is similar to looking through a dirty car windshield. It may be difficult for the individual to make out objects around them and navigate their surroundings.

In the final stages of cataracts, vision may be almost entirely obscured with a milky haze, which may be slightly translucent. There may be patches of thick, cloudy blind spots throughout the visual field.

As you age, your lenses naturally harden. In some people, this can cause a clouding in the lens known as cataracts, which blocks light from reaching the retina, causing blurred vision and sensitivity to glare. Cataracts are painless and are usually detected during routine eye exams. Corrective surgery is often recommended if the level of vision loss interferes with daily activities, such as driving or reading. Cataract surgery is highly successful, restoring vision in 97% of people.


No visual symptoms are present at this stage.

During the early stages of glaucoma, peripheral vision begins to darken and the individual must rely much more heavily on central vision.

With mid-level glaucoma, the darkening peripheral vision continues to grow toward the centre of one’s sightline. Often called “tunnel vision”, the effect is similar to looking through a pinhole camera.

As glaucoma progresses, peripheral vision is lost entirely, and only a small amount of vision may remain in the centre of the visual field.

In the final stages of glaucoma, the individual may be left completely blind or with only a small point of vision in the centre of the sightline. At its worst, Glaucoma damages the optic nerve resulting in total blindness.

Glaucoma is the second most common cause of vision loss in seniors in Canada. The condition involves damage to the optic nerve, which is often the result of a build-up of excess fluid, causing high pressure inside the eye. Glaucoma can begin without any symptoms and over time can advance to more severe stages, in which central vision narrows to “tunnel” vision or even result in a complete loss of vision. Through early detection and treatment, severe vision loss or blindness can be prevented.

Also available: CNIB iSimulator app for the iPhone

Use your iPhone’s built in camera to see how your vision could be affected by AMD, diabetic retinopathy, cataracts, and glaucoma and share the results by email, on Facebook and on Twitter. Download from iTunes today >

NOTE: This tool is designed to offer one representation among many ways that vision loss can be experienced by someone who is blind or partially sighted. Additionally, we do not promote the use of this tool as an alternative to medical advice and information provided by an eye doctor. This tool is for educational purposes only. We strongly encourage you to visit an eye doctor regularly for complete eye exams and to discuss your own unique vision health.

The CNIB EyeSimulator has been made possible with the support of an educational grant from Novartis Pharmaceuticals Canada Inc.