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)?

If night blindness symptoms are caused by hereditary retinitis pigmentosa disease, the symptoms and time of the disease may vary from patient to patient, since it is inherited.

Although night blindness (chicken black) begins to develop from childhood, the first symptoms are usually seen at a later age.

The main reason for this situation is that the disease progresses from the outside of the retina to the center and as a result of the cells in the retina being affected, the visual center ends up with the degeneration caused by the disease.

Although chicken black can affect both eyes, it is difficult to predict from the outset the rate of progression of the disease and the degree of vision loss. Although the disease does not cause permanent blindness, there is a narrowing of central vision and a gradual decrease in vision 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,

Apart from these symptoms, the disease can also be caused by different eye problems. If chicken black retinitis is caused by pigmentosa, they may also experience vision problems such as loss of central vision and tunnel vision.

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 simple and repeatable field test has been developed to measure the dark adaptation time of the eyes. With the night blindness test, the pigment cells in the patient’s retina are checked. In addition, the patient’s vision in dim light is evaluated during the test.

How is

Night Blindness (Chicken Black) Treatment?

The main rationale in the treatment of night blindness is to treat the underlying causes of the vision problem.

For the treatment of night blindness caused by cataracts, the damaged lens must be replaced.

For this purpose, a simple eye surgery can be planned. The surgically clouded lens is replaced with a new artificial and transparent lens. Thus, complaints such as night blindness and blurred vision are corrected.

• Vitamin supplements should be taken to correct night blindness due to vitamin A deficiency. People who have a balanced and regular diet are less likely to have vitamin A deficiency.
• However, the risk of vitamin deficiency increases in people who do not eat properly or in the presence of diseases that cause problems with absorption.
• Night blindness due to genetic conditions such as retinitis pigmentosa cannot be reversed. In retinitis pigmentosa, pigment begins to accumulate in the retina. This accumulation cannot be reversed by a method such as night blindness surgery or medication. Therefore, the treatment of night blindness due to retinitis pigmentosa is currently not possible.

People with this type of disease should avoid situations that could have dangerous consequences, such as driving at night.

Night blindness is a condition that can be prevented by taking certain precautions and the risk factors that may cause this problem can be controlled. The first method that comes to mind in the prevention of night blindness is to take the vitamin A needed by the body regularly.

Other measures that can be taken in addition to the vitamin can be listed as follows:

• Wearing Sunglasses:

Sun rays can damage the eyes and cause problems such as cataracts, macular degeneration and glaucoma. In order to prevent this, it is recommended to wear sunglasses, especially in sunny weather. The sunglasses to be preferred; It needs to protect the eye from all angles, block at least 99% of UVA and UVB rays, and filter 75-90% of visible blue light.

• Consuming Antioxidant Rich Foods:

Consuming plenty of antioxidant vitamins and eating antioxidant-rich fruits and vegetables helps protect eye health.

• Exercising Regularly:

Regular activity contributes to eye health by both regulating blood sugar and lowering the value of eye pressure.

• Having Regular Eye Examinations:

In order to closely monitor eye health, it is necessary to go for an eye examination every 1-2 years. Thanks to these controls, a possible health problem in the eyes can be detected at an early stage and treated immediately.

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.

Foods and beverages rich in these nutrients must be consumed regularly to protect 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.