How to Keep Glasses From Fogging Up

If you wear eyeglasses of any kind, whether they are goggles for water and snow sports, athletic sunglasses, safety goggles for work, or bog-standard prescription eyeglasses, you will be familiar with the all-too-common issue of glasses fogging up. Why is it that this irritating problem always happens at the most inopportune times, when you are concentrating and need crystal clear vision? 

If you have ever wondered how to stop this irritating and often stressful issue from occurring, you’ve come to the right place.

Before we get down to the nitty-gritty of how to stop the problem, it is worth looking at what causes glasses to fog up in the first place. 

Why Do Your Glasses Keep Fogging Up?

The problem of glasses fogging is the formation of condensation on the lenses of your glasses. What causes this? Well, water vapor, be it from a change in the ambient humidity levels of wherever you are, your breath or your breath, lands on a cool surface, such as your glasses lenses, it starts to cool down and then transforms into droplets of liquid. Those tiny droplets of liquid form a thin film of vapor over your glasses lenses that appear like fog. 

The lenses in your glasses, you see, are much cooler than your breath, particularly if you are outside in the cold air. As vapor forms on a surface with a lower level of thermal energy, a percentage of its own energy is transferred onto the surface.

Condensation is created when the vapor, or gas, does not have adequate energy to enable it to stay in gas form. As a result, it turns from a gas back into liquid form. The liquid particles have a lower level of internal energy than the gas form, but a higher level of internal energy than solid-state particles.

Matter exists in three distinct phases – gas, liquid and solid. The change that occurs from vapor/gas to liquid is what is known as a phase transition. Other common examples of this that you will be familiar with include evaporation (when a liquid transform into a gas), freezing (when liquid changes into a solid) and melting (when a solid transforms into a liquid). 

The primary cause for these changes is external forces and conditions such as pressure and temperature. As is the case with glasses as we have already discussed.

Now that we understand the science of it a bit better, how do you stop it happening?

How to Stop Your Glasses Fogging Up

Have Your Glasses Frames Adjusted

One way to prevent fogging from occurring could be to have your frames adjusted to allow a greater flow of air around the lenses. It may just involve the adjusting of either the arms or the nose pads. Even if you have them adjusted, if there is still the problem of fogging it could be that the size is not right for your face and it would be best having them remeasured and ordering a new pair.

Clean Your Glasses

How often do you clean your glasses? It could be that it’s actually not enough if you are experiencing fogging all too frequently. Scratches, smudges and dirt can make it easier for condensation to settle on the lenses. Handle your glasses more gently, keep them clean and avoid touching them with your fingertips. One of the best ways to clean a pair of glasses is with mild dish soap. These, interestingly, tend to have properties that can help reduce any fogging. Surfactants found in dish detergent can reduce tension on the surface of the lenses, resulting in a thin, transparent layer of water forming over instead of mist. 

Invest in Materials With Fog-Free Properties That Will Ensure They Stay Fog-Proof

One way to stop your glasses fogging up is by investing in lenses made from plastic and polycarbonate, which are both known to resist fogging. Another great option is having anti-reflective treatments fitting onto your glasses. Although designed to predominately reduce the issue of glare, as they often feature a coating with hydrophobic properties, they can resist smudging, water and fogging. 

Another option is investing in glasses that have an anti-fogging coating. This coating is applied to both sides of the lenses that are going to be used in your glasses before they are even cut. They feature a very hard and durable layer of protection against scratching and other problems. At a molecular level, the coating prevents tiny molecules of water from gathering up across the lenses and causing that fogging that is so often not just an irritation but quite dangerous too. 

If you invest wisely, you will have the benefit of glasses with lenses that seldom fog up, even when you are moving to and from a hot and humid climate to a cold environment. You won’t be able to stop a layer of water building up over the lenses, but as this is completely transparent, it is not in the least bit dangerous.

At Rx-Safety you can have the anti-fog treatment applied to lenses you buy from us that will last for the duration of the lenses’ lifespan and you can learn more about them here.

Alternative Products and Solutions

In addition to our anti-fog treatment for lenses, we also sell a few alternative products and solutions you may find useful on existing pairs of glasses that can work temporarily for anything from a few hours to a few days. By far the best option is the Cat Crap Paste. You can take a better look at these products here.

The seriousness of the lenses in your glasses, whether they are a prescription pair or not, should not be underestimated. In normal situations, it may be a minor convenience, but when you are participating in sporting or work activities that require crystal clear vision at all times, it can cause problems. The guide above, we hope, will help you avoid the issue and keep your glasses free from fogging. 

  1. Stephen Ryan says:

    There are some ways to stop safety glasses from fogging up. Polish your safety glasses with fog-killing wipes. Spray anti-fog solutions. Try home remedies such as dishwashing liquid or bar soap. Apply a shaving cream. Use defogging sprays. Purchase safety glasses with anti-fog lens coating. Hope these ways can help someone.

  2. Carlos R Popoca says:

    If I order on line, how can I be sure they’ll fit correctly? I have a prescription from America’s best. But they don’t have the safety glasses I need for construction.

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