International Day of Persons With Disabilities: Visual Impairment

Visual impairment characteristics are a key focus on December 3rd, the International Day of Persons With Disabilities. The United Nations established this day in 1992 to promote the rights and well-being of people with disabilities in all parts of society.

According to UN data, approximately 15% of the population lives with some disability. International Day of Persons With Disabilities provides awareness for a variety of these disabilities.

Visual impairments are some of the disabilities highlighted on this occasion. Most people will experience a visual impairment at some point in their lives. This makes it important to understand more about these impairments, their causes, and characteristics.

An impairment is “the diminishment or loss of ability in an anatomical structure or a physiological or psychological function.” Visual impairments specifically refer to diminished functioning or ability in the visual system.

The AAO specifically defines visual impairment as “ 20/40 vision, or worse, in the better eye, even with eyeglasses.” Patients are still able to use their vision, but may not be able to perform basic tasks without assistance.

In comparison, those that are considered legally blind have a visual acuity that is worse than or equal to 20/200, or their visual field is less than 20 degrees in diameter

Conditions that cause visual impairment can have serious consequences if left untreated. However, many of these consequences can be mitigated or avoided through quality eye care.

There are a number of characteristics associated with visual impairment. Some common visual impairment characteristics include:

1. Reduced visual acuity: The patient has difficulty seeing objects from near or close vision.

2. Blurred vision: Objects appear hazy or out of focus.

3. Tunnel vision: Limited ability to see things from the side, above, or below central vision.

4. Light sensitivity: Pain or discomfort when exposed to bright light.

5. Night blindness: Difficulty adjusting to low or dim light.

There is no single sign that a patient has a visual impairment. But a patient may be experiencing visual impairment and should see an eye doctor if they are:

• Bumping into objects

• Moving hesitantly or hugging the walls

• Touching or grabbing objects in an uncertain way

• Squinting or tilting their head to see things

• Having trouble distinguishing faces

There are a number of conditions that can cause visual impairments. These conditions range in severity and frequency. Here are some common types of visual impairments patients should be aware of.

Refractive errors occur when the shape of a patient’s eye keeps light from focusing correctly on their retina, causing blurred vision. Refractive errors are the most common type of eye condition. They include:

• Myopia (nearsightedness): Difficulty seeing objects from far distances.
• Hyperopia (farsightedness): Difficulty seeing objects at close distances.
• Astigmatism: An uneven curvature in the cornea which can cause blurry, fuzzy, or distorted vision.

A cataract is the clouding of the normally clear lens in the eye. In a healthy eye, the lens bends and refracts light, allowing us to see clearly. If someone develops a cataract, this normally clear lens begins to cloud.

As the lens continues to cloud, patients may experience other issues such as blurry vision, trouble reading, or in serious cases, vision loss.

Glaucoma is a progressive eye disease that targets the optic nerve, usually associated with high pressure inside the eye. If left untreated, glaucoma can lead to vision loss and blindness.

Since glaucoma comes with few warning signs, regular exams with an eye specialist are important for early detection and to prevent severe visual impairment.

Macular degeneration, or age-related macular degeneration (AMD), develops when cells in the macula (an oval area in the central portion of the retina) deteriorate, impacting vision.

Macular degeneration is the leading cause of vision loss in older Americans. An estimated 6% of people in the US aged 40 and older have some stage of this medical condition.

Diabetic retinopathy occurs when the retina’s blood vessels swell, leak, or close off, which can cause abnormal new blood vessels to develop on the retina.

Early-stage diabetic retinopathy can be mild and may require no treatment. In advanced stages, however, it can lead to bleeding in the eye, retinal tears or detachments, and blindness.

As there are a variety of visual impairment characteristics and types of visual impairment, there is no single treatment for all cases. Patients who are experiencing visual impairment should see their eye doctor for a comprehensive eye exam to understand more about the causes and treatment for their condition.

During the exam, the doctor will run vision tests together with specialized tests to identify eye diseases which may be responsible for impairment. From there, the eye doctor may offer a variety of treatment options depending on the details of the patient’s condition.