Is it bad to see at night? Let's talk about night vision (Scotopic Vision)

Imagine that you have been in the sun and suddenly went into a dark room, for example, a movie theater. Or when you are walking on the street at night, in a place without lights, it takes a while to see your surroundings, right? That is what we call night vision, or in medical terms , scotopic vision . This is an amazing ability of our eyes.

How does this night vision work?

This is a very interesting process. Simply put, it's a bit like how a camera works. Let's see how this works.

Imagine you went from being in a well-lit place to a dark place.

1. The pupil of the eye enlarges: The first thing that happens is that the black part in the middle of your eye, the pupil , enlarges to let in as much light as possible. It's like magnifying the lens of a camera.

2. Light enters the retina: The light that enters the eye in this way hits a screen-like area called the retina at the back of the eye.

3. Special cells begin to work: There are millions of special cells in the retina that are sensitive to light. We call these photoreceptors . These are of two types.

• Cones: These help us see colors in good light.
• Rods: Here are the heroes of our story. These ``rods`` are the cells that help us see in low light, that is, at night.

4. A chemical process begins: After you enter the dark, within a few minutes, a protein called rhodopsin in your rod cells starts to activate. This entire process takes about 30 minutes to complete, and you can see at your best in the dark. Have you noticed why you suddenly can't see in the dark?

5. The message goes to the brain: Activated rod cells convert this low-level light into electrical signals and send them to the brain via the optic nerve .

6. The brain creates the image: Finally, your brain translates these signals and creates the image you see in the dark.

What are the medical conditions that affect night vision?

Our night vision depends on the health of the rods in our retina. So anything that damages these cells can impair our night vision. Here are some of the conditions that can cause this.

Why can animals see better at night than we do?

This is a problem that many people have. Animals like cats and dogs can see better at night than we do. There are two main reasons for this.

1. Big eyes: Animals' eyes and retinas are larger than ours, so their eyes can gather a lot of light even when there is little light.

2. The luminescent membrane: Behind the retina of animals, there is a membrane called the tapetum lucidum . This works like a mirror. Light entering the eye passes through the retina, hits this membrane, and is reflected back to the retina. That is, the light hits the retina twice instead of once. This is why they can see clearly even in very dark conditions. Have you ever seen a cat's eyes glow when a light shines on them at night? That is because of this membrane called `(Tapetum lucidum)`.

How do we keep our night vision good?

Our eyes are a very valuable resource. So it is our responsibility to protect them. Here are some things you can do to keep your night vision good.

• Get your eyes checked regularly: Even if you don't wear glasses, it's still important to have your eyes checked by an eye doctor at least once a year . This way, any problems can be identified early.
• Get a complete health checkup: Diseases like high blood pressure and diabetes can directly affect your eyes. So, visit your doctor regularly for a complete checkup.
• Wear good sunglasses: Wear sunglasses with 100% UV protection (UV400) to protect your eyes from the sun's harmful ultraviolet (UV) rays. Do not look directly at the sun.
• Avoid smoking: Smoking can damage the delicate blood vessels in your retina. This also affects your light receptor cells.
• Eat a healthy diet: Foods rich in antioxidants are very important for eye health. Eat a diet rich in fruits, vegetables, legumes, and healthy fats.

You now know a lot about this amazing ability called night vision, which helps us find our way in the dark and navigate indoors. To preserve this ability, it is essential to take care of your eyes. If you experience any changes or discomfort in your night vision, do not ignore it and seek medical advice immediately.