Night Vision: What is it?

Night Vision is the ability to see in low-light conditions. There are several core differences between the vision during the daylight and that during the night: The pupils become larger and the eye permits more light when the environment is dark. A different, more sensitive kind of cell in the eye – rod cells – collects the light for Night Vision. The Color Vision is bad under very low-light conditions.

Night Vision: Its symptoms

Some of the most common symptoms that people have at night are to see things, not really close to them, as blurry vision, flash or halos surrounding the lights. Night Vision problems may increase the risk of falling down or make it difficult for someone to drive with safety.

As the pupils are becoming larger in the dark, some people get more myopic as compared with daylight. This night myopia could make the distant things look vague, a situation that maybe signals the need of eyeglasses or a change of the eyeglass lens or the change of your contact lenses.

Diseases and conditions that may affect the Night Vision include:

• When one sees well from a close distance, but not from a far distance
• It is a disease of the optic nerve that interlinks the eye with the brain
• Pilocarpine, is a drug used for Glaucoma which tightens the pupil, causing a contracture
• Cataracts that cause blurriness in the normal crystalline lens of the eye
• Uncontrolled Diabetes Mellitus
• Retinitis Pigmentosa
• Vitamin A deficiency
• Keratoconus with the cornea having a large curvature

Nyctalopia (Night Blindness): What is it?

Nyctalopia, also known as Night Blindness, is a condition that makes it difficult or impossible for one to see in relatively low-lighted environment. It is a symptom of many eye diseases. Nyctalopia can exist since one’s birth or may be caused by injury or malnutrition, such as the deficiency of vitamin A. It can also be described as the deficient adaption in darkness.

Not surprisingly, most people do not see well in the darkness. However, some people find it difficult to see at night or in low-light. Nyctalopia does not mean that you cannot see at night, but that your vision becomes poorer in dim light.

Nyctalopia itself is not a disease but rather a symptom of another eye disorder. In some cases, high myopia can make it harder to see at night or in low-light environments. Certain cells in the retina of the eye are responsible for allowing you to see in dim light. If a disease or a disorder affects these cells, it causes night blindness.

Nyctalopia: Which is the most common cause

Nyctalopia’s most common cause is the Retina Pigmentosa, a disorder when the rod cells of the retina gradually lose their ability to respond to light. Patients who suffer from this genetic disorder have progressive Nyctalopia and finally, their day vision may be affected too. In the relevant night blindness that is connected with the chromosome X, the rods since birth do not function at all or they function to a small degree, without their condition deteriorating.

Another cause of night blindness is the deficiency of Retinol, found in the fish oils, the liver and the dairy products. Due to the outer region of the retina consisting of more rods and fewer cones, loss of the Peripheral Vision results. 

Nyctalopia: Its symptoms

For many of us, driving in the dark is not a big deal. But for other people, driving in darkness is uncomfortable, if not unpleasant. Some things that affect us when driving at night are the halos and the flashes around lights. The pupil dilates in darkness so as to allow more light to enter the eye. We can see it when our eyes “adapt to darkness”. As the pupil dilates, the Vision Acuity deteriorates and, in many cases, this leads to the perception of halos or rings around the car headlights or the street lights.

Glare can be described as hardly seeing in bright conditions and can lead to distortion of the objects, discomfort or distraction. The halos and the glare are usually caused by a spherical aberration, which is common to everyone and cannot be fixed with standard glasses or contact lenses.

In order to assess the Night Vision, your ophthalmologist may ask you some questions, examine your eyes and test your vision ability. A common examination is the contrast sensitivity chart in the Pelli-Robson table. It is like Snellen’s eye-testing letter chart, but with letters in various shades of grey. This test measures how well you can see the contrast between black and grey letters on a white background.

Concerns related to Night Blindness

If you are wondering whether you have Night Blindness or not, examine the following questions:

• Do you face any difficulties in moving around at home during the night, even with small lights?
• Is the driving at night getting more difficult for you?
• Do you avoid going out at night, because you fear that you will fall down?
• Is it hard for you to recognize people’s faces in dark conditions?
• Does it take you enough time to adapt to the light when coming from dark conditions?
• Likewise, does it take you enough time to adapt to a dark room?

If you have any worries concerning your ability to see in the dark or dim light, talk immediately to your ophthalmologist. A complete examination of your eyes will help you in spotting any disorder that may affect your vision.

Nyctalopia: Which is the treatment

The treatment of Nyctalopia depends exclusively on its cause. If your refractive error (or refraction error) is significant, a new prescription of eyeglasses may be all you need for a better vision in low-light conditions. In certain cases, cataract removal may be a relief for your vision while there are not home exercises that can improve the Night Vision.

The immediate medical treatment of any underlying conditions will maintain as long as possible your vision. Your doctor may help you understand what is best for you.

Nyctalopia and Acupuncture

The action of Medical Acupuncture as a complementary treating method has an effect on the autonomous nervous system, the improvement of oxygenation and the metabolism of cones and rods and consequently acts as an aid to the mechanism of adaption to darkness, thus contributing to the improvement of Night Vision.