Shedding Light on Night Blindness
It’s no surprise that most people don’t see well in the dark. However, some people have considerable difficulty seeing at night or in poor light. This is called night blindness (eye doctors call it nyctalopia).
Night blindness doesn’t mean you are completely unable to see at night, but that your vision is poorer then. It is not a disease in itself, but instead is a symptom of some other type of vision problem.
In some cases, being very nearsighted (myopic) can make it hard to see at night or in low light.
Certain cells in the eye’s retina are responsible for allowing you to see in dim light. If these cells are affected by a disease or condition, night blindness occurs.
Some of the eye conditions that can cause night blindness include:
- Nearsightedness (seeing well up close but not far away)
- Glaucoma (a disease of the optic nerve connecting the eye to the brain)
- Medicine for glaucoma that constricts (narrows) the pupil
- Cataracts (cloudiness of the eye’s naturally clear lens)
- Diabetes (uncontrolled blood sugar levels)
- Retinitis pigmentosa (an eye disease that causes blindness)
- Too little Vitamin A
- Keratoconus (having a cornea that is very steeply curved)
Is bumping and tripping through your darkened house normal or a symptom of something else?
If you aren’t sure whether you have night blindness, consider the following questions:
- Do you find yourself having trouble moving around your house at night, even with small night lights?
- Is driving at night becoming more difficult?
- Do you avoid going outside at night for fear of tripping?
- Do you have trouble recognizing people’s faces in darkened settings?
- Does it take your eyes a long time to adjust to light when coming in from the darkness?
- Similarly, does it take you a long time to adjust to seeing anything in a darkened room?
If you have any concerns about your ability to see in the dark or in dim light, speak with your ophthalmologist right away. Having a complete eye exam will help identify any condition affecting your vision.
Treating night blindness depends solely on its cause. If your refractive error is significant, getting a new prescription for your eyeglasses may be all you need for better vision in low light. In some cases, having cataracts removed can be illuminating as far as your vision is concerned. Your ophthalmologist can explain what is causing your night blindness and suggest how to brighten your outlook.
Seeing Night and Day
Night vision and day vision are naturally different.
Here are some facts about your eyes in the dark:
- They are basically color blind, seeing mostly black, white and grey;
- They have lower levels of visual acuity;
- There is an area in your central field of vision that is less clear;
- You see moving objects better than stationary objects.