Seven Things to Know About Night Vision

Seeing well at night is something we may take for granted until it starts to get hard to do. As our ability to see well at night changes, it may impact driving and safety. Learning more about night vision helps determine what declining night vision may mean and what you can do about it. The article below covers seven things to know about night vision. 

How seeing in the dark works

Your ability to see in the dark mostly involves two structures in the eyes, your retina and iris. The retina contains two types of photoreceptor cells that help detect light called cones and rods. The cones play a role in color vision and fine details. The rods mainly allow vision in dim light.

The iris contains the muscles that narrow or widen the opening of the pupil to adjust how much light enters the eyes. If the iris does not narrow quickly enough, too much light can enter, which causes light sensitivity and makes seeing in bright light difficult. If the iris does not work correctly, it can also affect how much light gets to the retina. This may reduce your ability to see well in dim light.

Signs you may have poor night vision include:

• Trouble seeing in dimly lit rooms
• Needing additional light for reading
• Eyes needing more time to adjust to light
• Problems driving at night 

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Facts about night vision

Below are several facts related to night vision, including causes.

Poor night vision has a name. Problems seeing at night are sometimes referred to as night blindness. Night blindness does not mean you completely lose your vision in the dark. Instead, it refers to trouble seeing in dark or dim settings. This might happen if your eyes have difficulty adjusting to changes in brightness.  

Night blindness is not a disease in itself. Instead, it can be a symptom of age-related changes or eye diseases, such as cataracts.

A vitamin deficiency can contribute to poor night vision. Although uncommon in the United States, in some parts of the world, vitamin A deficiency can cause night blindness.

Glaucoma and cataracts can lead to trouble seeing at night. Decreasing night vision is very common. According to the American Academy of Ophthalmology, a few eye conditions can cause problems seeing well in dim light, including cataracts and glaucoma.

Poor night vision can affect driving. The intermittent brightness from headlights may contribute to difficulty seeing at night while driving. If you have this difficulty, try to do most of your driving during the day.

Age-related changes that may affect night vision. As we age, our eyes react slower to changes in light. The photoreceptors need a little more time to adjust when we move from bright light to a dimly lit space.  

There is no specific treatment for night blindness. There is no one treatment to improve how well you see at night. However, if poor night vision developed due to an eye disease, such as cataracts, treating the underlying cause may help improve sight in dim lighting. Also, if you wear glasses, consider glasses with anti-reflective coating to reduce glare from streetlights and headlights.

If you would like to ask whether an appointment with one of our eye doctors would be appropriate at this time, call our office at 508-746-8600.