Can You Start a Fire With Nearsighted Glasses?


Most kids have started a fire with a magnifying glass. After I learned how to do it, I just couldn’t stop starting fires with every paper around. Now, to have a magnifying glass at your disposal all the time is unlikely. Chances are that you won’t have one with you when you need it. For example, when you are in a survival situation.

So, I wondered what would be another way to start a fire when you don’t have a match or a lighter available. After all, fire is one of the most important human discoveries for a reason. When out in the open, the ability to start a fire may save your life. The fire cooks the food, keeps you warm, sends dangerous animals away.

Maybe you have already seen, but it’s possible to start a fire, on a sunny day, with your glasses. Once you learn this the question that arises is can you do it with any type of glass? Can you start a fire with nearsighted glasses? The answer is no. Unfortunately, you can’t start a fire with nearsighted glasses. Those glasses have diverging lenses that disperse the sunlight beam once it hits the glasses instead of focusing the heat in a single point.

Burning Read?

It is time to put your reading glasses to use, especially if you are not the bookworm type.

To put it simply, it’s important to know that there are two types of lenses used in glasses. If you are nearsighted, you use a diverging lens. With this lens, the light hits the glass, and it immediately diverges into different beams. Never creating a single focal point. That is why you can’t really start a fire with this type of lens.

Here’s how it actually works. For you to start a fire with the sunlight, you need to find a way to focus the light beam. So, what you need is a type of lens that will focus all the light into one single point. In this case, the paper or any other flammable material you are using.

Now, the converging lens, which is the one in your reading glass, takes all the light beam and turns it into a single focal point. It is like receiving various laser lights and turning them all into one. This way, it helps the fire to get started.

If you have any type of farsighted glass, even the cheap ones that you can find in certain stores, it is possible to make it work. So, perhaps even if you don’t need one for your vision, you might consider getting one.

So, to make it as clear as possible, you have to use a converging lens and not diverging lens. This basically means that you’re going to need reading glasses and not nearsighted glasses. There are a few people who claim that you can use water to make it work but that’s not the truth with nearsighted glasses.

And for those wanting an easier and simpler way to start a fire, click here for a fire-starting item that is highly rated on Amazon.

How to Fire Up the View?

So, let’s start on the principle that you’re not going to be able to start a fire with nearsighted glasses. You can still do it with reading glasses. What you’re going to want to know next is how to actually do it. The idea behind this method is fairly simple and easy to implement. All you’re going to need is:

  1. Reading glasses
  2. A flammable material like paper
  3. A sunny day
  4. Perhaps water

What you’re going to do is to point the lens to the paper, directing the sunlight beam to it. A great tip here, in case the paper is a newspaper or any kind of paper that has ink, is to point at the written part. This is because the darker surfaces absorb the heat, which in turn catches fire quickly. So, point it at the headline in the case of a newspaper.

Once it begins to produce smoke, you may blow it to ignite the fire faster. In case you have any difficulty starting the fire, there’s still one trick that you can do to help you out. If with this trick the method still doesn’t work, it’s probably because the sun is not strong enough.

If you use one drop of water on the lens, it sorts of acts as a magnifying glass, which will potentialize the sunlight that is hitting the spectacles. This will ignite the fire faster. It is important to highlight though that you have to have a very sunny day outdoor otherwise the sunray will not be strong enough to heat the material all the way to combustion.

Can You Convert Diverging Into Converging?

There are people who claim that it is possible to turn a diverging lens into a converging one just by applying a few drops of water onto the lens. This is simply not true. Unfortunately, there is no way that you can turn your nearsighted glasses into a converging lens. If you want to start a fire using this method, you’re going to need a magnifying glass or a converging lens.

Now, if you tried this method and is not working too well for you, you can also utilize certain methods to increase the power of your available lens. Here’s the thing, if your lenses are too thin, it may not work well for starting a fire. So, your option, besides the water drop method, is to put one lens on top of the other to maximize the sunlight when it hits it.

As you can see, there are two ways that totally work for you to maximize the power of the lenses. There’s no way, unfortunately, to turn the diverging lens into a converging one. So, if you find yourself in need to start a fire, you’re going to either need a magnifying glass or converging lens.

It is also important to point out that you need a sunlight and it has to be a sunny day. If you use any other form of a light source such as a flashlight, it will not work with this method.

Magnifying Glass

The magnifying glass is the best method to start a fire with a beam of light. The reason is that the magnifying glass has a biconvex lens. This type of lens is curved in both directions. For example, a normal lens used in glasses both the nearsighted and farsighted are curved in only one direction. This makes the light bend both when it enters the lens and when it leaves it.

This curved lens produces a more powerful and focused beam of light, thus making it easier and faster to ignite the paper or whatever other material you are using for this. Just remember to always point to the darker portion of the paper. The closer to white the worse and the closer to black the better.

Now, you may also hear about a method of using the magnifying glass with the farsighted glass. This method would involve putting one on top of the other to create a more powerful beam of light, thus starting a fire easily. This is simply not the truth. It will either not make any difference or actually slow down your results.

Final Thoughts

So, as you can see, the nearsighted glasses will not be of much help when it comes to starting a fire.

Unfortunately, there is no way of turning this around and making it work for you. You are either going to need a magnifying glass or farsighted glass to make this work. With one of those options, you’re going to need a sunny day with enough heat to start the fire, and the flammable material.

A drop of water on your reading glass can amplify the beam of light and make it easier for you. As a final note, it is also important to remember that as you as you see the smoke get started, you can help by blowing it to make the fire start faster. For those who still want a simple solution to wanting to start a fire in an effective but primitive way, I found an item found a fire-starter on Amazon that is compact and fits in your pocket. Click here to get the latest pricing.

Related Questions

What are other easy methods to start a fire?

Besides a lighter and matches, you can start a fire with other methods but they are not as easy. To put it simply, you need a conductor and a fuel to start a fire. Alcohol, for example, is a great fuel while wood is a great conductor. So, to make things easy on you look for wood or paper. If you don’t have a lighter or matches, you’re going to need another source of heat. Be it the sun or friction.

Can I use my glass for another thing in a survival situation?

Besides making it easier for you to see things, your nearsighted glass won’t have much use. Since most lenses are now made of plastic, you can’t really turn it into weapons. So, the best you can do is to keep them to make sure you’re seeing everything perfectly.

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