Night Blindness

What is Night Blindness?

Night Blindness, which is also known as chicken black among the people, manifests itself due to the inability of the eye to adapt to dark environments. Normally, in a healthy person, the eyes also adapt quickly in the transition to dim light. In this case, it does not cause complete blindness, although it affects vision in the direction of weak light or inability to see adequately in the dark.

Such problems are also known as nyctalopia. Since it is a result of different diseases, it is not considered a disease in itself. Retinitis Pigmentosa is the most common cause among these diseases. This condition affects the photoreceptor cells responsible for vision in the retina, the layer of the eye that perceives the lower light.

The age at which night blindness occurs and the way it progresses, the degree varies according to individuals.

Why does night blindness occur?

There are cells in the retina that help to see in light and dark places. These cells fulfil the function of vision by adjusting the light level inside the cell when the light is insufficient.

The main cause of reduced vision is the deterioration of photoreceptor cells in the retina. As a result of these, different function problems may occur in the perception of light. Night Blindness can also be caused by

• Myopia
• Cataract
• Diabetes
• Glaucoma
• Vitamin A deficiency
• Keratoconus
• Retinis Pigmentosa
• Usher Syndrome

In addition to all these, some corneal surgeries and drug treatments are also among the causes of Night Blindness.

Symptoms of Night Blindness

Symptoms of night blindness can manifest themselves in different ways. If it is caused by genetically inherited retinitis pigmentosa disease, the symptoms and time differ from person to person. Although it usually occurs in childhood, symptoms can also be seen at a younger age.

Although the condition affects both eyes, the rate of progression and the degree of visual loss are difficult to predict from the beginning. Although the condition does not lead to permanent blindness, there is a narrowing of central vision and a progressive reduction in low light. Night Blindness has symptoms such as

• Inadequate vision and narrowing of the visual field in low light
• Adaptation problems when entering a dimly lit environment from a high light environment
• Sensitivity to light and blurred vision after exposure to intense light

Symptoms of night blindness can also be caused by different eye problems.

Diagnosis of Night Blindness

For the diagnosis of night blindness , the transition from light to darkness is measured. For this, a field test is performed. The test checks the pigment cells in the patient’s retina. Finally, the quality of vision in dim light is analysed.

Electroretinography and fundus examination can also be performed to determine whether there is an underlying eye disease. Early diagnosis and treatment are as important as many diseases related to eye health.

How is Night Blindness Treated?

More than one disease can play a role in the occurrence of night blindness. In order to determine the exact treatment method for the patient, it is necessary to diagnose the disease underlying the vision problem. In this context, the patient who complains of severe vision loss at night and in dim light should be examined in detail by an ophthalmologist.

If the main cause of Night Blindness is due to cataract or keratoconus, surgery option can also be used. It is possible to perform intraocular lens replacement with smart lens operation for cataract surgery, thus improving night vision with clear vision at all distances.

Hard contact lenses used in the treatment of keratoconus disease can also provide improvement in night vision as well as refractive problems of the eye.