What is Night Blindness (Chicken Black)?

What is Night Blindness (Chicken Black)?

Night Blindness is a problem of reduced vision and visual acuity that occurs at night or in poor light conditions. Night blindness has passed into the medical literature as nyctalopia.

The disease, known as chicken black among the people, can occur for many different reasons. However, it has been particularly characterized by retinitis pigmentosa.

What Causes Night Blindness (Chicken Black)?

Night blindness can be caused by a problem with the ability of the cells in the retina to see in dim light, or it can occur as a result of a vitamin deficiency or another eye defect. Problems in the rod-shaped cells in the retina layer of the eye that enable black and white vision are an important cause of night blindness.

Some of the factors that cause night blindness can be listed as follows:

• Age:

As the person ages, the pupils may lose their ability to dilate and narrow somewhat. Insufficient dilation of the pupils in the dark or in dim light results in a decrease in the amount of light entering the eye. This causes night blindness. In addition, the transparency of the transparent layer called the cornea, which covers the surface of the eye, decreases with age. This negatively affects the contrast sensitivity of the eyes in the dark.

• Presbyopia:

Presbyopia is an eye defect that occurs with age. In this defect, there is a decrease in the eye’s ability to focus and adjust to light changes.

• Myopia:

Night vision may also be impaired in myopia with farsightedness.

• Eye Blood Pressure (Glaucoma):

Eye pressure or glaucoma is an increase in intraocular pressure. In glaucoma, which affects peripheral vision, the vision problem becomes especially evident in the dark and while driving.

• Some Drugs Used in Eye Blood Pressure:

Eye pressure medications that constrict the pupils can cause a decrease in the amount of light entering the eye, resulting in impaired night vision.

• Cataract:

Cataract is a condition in which vision becomes blurred due to a decrease in the transparency of the lens of the eye inside the eye. Cataracts cause difficulty in driving, especially when driving at night, as the headlights of oncoming vehicles cause discomfort to the eyes.

• Diabetic Retinopathy:

Diabetic retinopathy, a condition caused by the damage of diabetes to the retina layer at the back of the eye, can cause serious vision loss. The Diabetic retinopathy, one of the leading causes of retinal blindness in adults aged 20 to 64 years, can develop permanent and total blindness if left untreated.

• Retinitis Pigmentosa:

A rare genetic disease in which dark pigment collects in the retina. This changes the way eyes respond to dim light. In the disease, retinal photoreceptor cells, namely rods that provide black and white vision and cone cells that provide color vision, begin to deteriorate. Therefore, there is no cure and eventually progresses to permanent blindness.

• Vitamin A or Zinc Deficiency:

Vitamin A and zinc deficiency can trigger night blindness. Although rare, not getting enough vitamin A in the diet can affect night vision. Since zinc helps the body absorb vitamin A, its deficiency can also cause night blindness. Night blindness caused by vitamin A or zinc deficiency causes symptoms that can be prevented or treated.

• Keratoconus:

The thinning and tapering of the cornea, the outermost layer of the eye, is called keratoconus. Keratoconus progresses over time, causing deterioration in night vision.

• Exposure to The Sun:

Sun exposure without proper eye protection can temporarily impair night vision.

Night blindness, which is usually caused by the sun, resolves within two days. It is possible to prevent this situation by wearing sunglasses that protect against ultraviolet rays.

• Complications Following LASIK Eye Surgery:

LASIK eye surgery is a method of correcting distance or near vision defects using laser. Although rare, patients who have had LASIK eye surgery may have impaired night vision after surgery. The most common complaint is glare or halos around lights at night.

What are The Symptoms of Night Blindness (Chicken Black)?

When night blindness is caused by hereditary retinitis pigmentosa, the symptoms and progression of the condition can vary significantly between individuals due to its inherited nature.

While night blindness, also known as “chicken blindness,” typically begins to manifest in childhood, the initial symptoms are often more noticeable at a later stage in life.

This occurs because the disease primarily progresses from the peripheral areas of the retina toward the center. As the retinal cells are gradually affected, degeneration eventually impacts the visual center.

Although night blindness usually affects both eyes, it is challenging to predict the rate at which the condition will advance or the extent of vision loss early on.

While this disease does not lead to complete blindness, it does result in a narrowing of central vision and a progressive decline in the ability to see in low–light environments.

The Symptoms of Night Blindness Are As Follows:

• Insufficient vision and narrowing of the visual field in low-light environments,
• Having a visual adaptation problem when entering a dim environment from an environment where there is a lot of light,
• Sensitivity to light and blurred vision after exposure to intense light,

These patients may bump into objects while walking, or they may not be able to perform tasks that require detailed close vision alone due to problems in central vision. In addition, chicken black disease can cause problems in seeing different colors in some patients.

Which Vitamin Deficiency Is Night Blindness (Chicken Black) Occur?

Vitamin A deficiency can cause night blindness. Vitamin A, also known as retinol, is a molecule located in the light-sensitive area of ​​the retina and plays a role in turning nerve messages into pictures. In vitamin A deficiency, problems may occur in this transformation and night vision is affected.

Diseases such as pancreatic insufficiency, cystic fibrosis; It may predispose to a deficiency of vitamin A, a fat-soluble type vitamin. Therefore, people with these diseases are also at risk for night blindness. Night blindness is a disease caused by vitamin deficiency. Getting enough vitamin A along with the diet is very important in preventing night blindness.

Foods rich in vitamin A can be listed as follows:

• Carrot
• Melon
• Pumpkin
• Mango
• Spinach and other dark green leafy vegetables
• Liver-like red meat products
• Milk
• Egg

How is Night Blindness (Chicken Black) Diagnosed?

Together with the general eye examination, if the retinal findings of the disease are established, we can diagnose the disease by performing a fundus examination.

Here, we can list the three prominent findings as increased pigmentation in the retina, thinning of the vessels and pale vision in the optic nerve.

In cases where these findings are not seen, other diagnostic methods are applied. In addition, the disease can be easily diagnosed by genetic analysis.

How is The Night Blindness (Chicken Black) Test Performed?

A straightforward and consistent field test has been designed to assess the dark adaptation time of the eyes. This night blindness test examines the pigment cells in the patient’s retina and evaluates their visual performance under low-light conditions.

How is Night Blindness (Chicken Black) Treatment?

Addressing night blindness effectively begins with tackling the root cause of the issue, as this vision problem often stems from underlying health conditions that require tailored treatments.

Here’s how different causes of night blindness can be managed:

• When cataracts are the culprit, the solution typically involves replacing the damaged lens. This is achieved through a straightforward and commonly performed eye surgery.
• During the procedure, the clouded lens is carefully removed and substituted with a clear, artificial lens.
• As a result, both night blindness and associated symptoms like blurry vision are significantly improved, restoring clarity to your sight.
• If a vitamin A deficiency is behind the challenge, the focus shifts toward replenishing this crucial nutrient. Vitamin supplements are an effective remedy in such cases.
• Thankfully, individuals who maintain a balanced and nutritious diet are much less likely to face deficiencies in vitamin A or experience related vision problems. By addressing these underlying causes, you can not only improve night-time vision but also enhance overall eye health and well-being.

However,

• The risk of vitamin deficiency increases in people who do not eat properly or who have diseases that cause absorption problems.
• Night blindness due to genetic disorders such as retinitis pigmentosa is irreversible.
• In retinitis pigmentosa, pigment begins to accumulate in the retina.
• This build up isn’t something that can be undone through procedures like night blindness surgery or by taking medication.

Therefore,

• There is currently no cure for night blindness due to retinitis pigmentosa.
• People with this condition should avoid situations that could lead to dangerous consequences, such as driving at night.
• Night blindness is a condition that can often be avoided by adopting specific precautions and effectively managing the risk factors associated with its development.

  The first method that comes to mind in preventing night blindness is to regularly take vitamin A, which the body needs.

In addition to vitamins, other precautions that can be taken include:

Wearing Sunglasses:

• Sunlight can damage the eyes and cause problems such as cataracts, macular degeneration, and glaucoma.
• To protect your eyes, consider wearing sunglasses, particularly on bright, sunny days.
• The preferred sunglasses should protect the eyes from all angles, block at least 99% of UVA and UVB rays, and filter 75-90% of visible blue light.

Consuming Antioxidant-Rich Foods:

• Eating plenty of antioxidant vitamins and antioxidant-rich fruits and vegetables helps protect eye health.

Regular Exercise:

• Regular activity contributes to eye health by regulating blood sugar and lowering eye pressure.

Having Regular Eye Examinations:

• It is necessary to have an eye exam every 1-2 years to closely monitor eye health. These check-ups allow for the early detection and treatment of any potential eye health issues.

What Should Be Done to Prevent Night Blindness (Chicken Black)?

As with all other eye conditions, a healthy lifestyle is very important for night blindness. The best steps you can take are to avoid smoking, reduce alcohol use, and eat healthy foods. Antioxidants, alpha-lipoic acid, omega 3 fatty acids, vitamins A and C, and zinc are important for eye health.

You can also take nutritional supplements in addition to your daily diet. However, you should always consult your doctor before you start taking supplements.

If you have difficulty distinguishing between objects at night or see halos around lights in the dark, you should definitely talk to your eye doctor. Because these symptoms can be early signs of a serious eye disease. In such cases, early diagnosis is vital to prevent serious problems.