Health + Prevention

How do I disinfect my glasses and how do I stop the lenses fogging up when wearing a face mask?

2 September 2020
  • How do I disinfect my glasses?

The COVID-19 pandemic has made the whole world aware of the importance of washing hands. But it’s not the only reason to maintain good hygiene. To prevent the spread of any harmful germs, you need to maintain a general hygiene routine. BETTER VISION explains why and how you should disinfect eyeglasses, smart devices and other high touch items, and gives tips on how to avoid foggy glasses with a mask.

Germs can be found anywhere, including on various surfaces in our homes and on items we use on a daily basis. But there’s no reason to be fearful, as it is possible to get rid of most of it with a few simple hygiene practices.

Washing your hands is a proven practice to ensure cleanliness, but it is not the only sensible protective measure against the spread of harmful germs. In your household, surfaces such as door handles, light switches, taps and counters should be cleaned thoroughly to minimise the spread of germs.

Other items that are sometimes neglected from regular cleaning are personal items that we constantly use and touch. These items are referred to as high touch items, and include:

  • Smart devices (mobile phones, tablets and smart watches) and computers (laptops, monitors and keyboards)
  • Eye glasses
  • Bank cards
  • Car keys, wallets and handbags

Why it’s important to clean high touch items

High touch items can become contaminated by germs through direct contact with improperly washed hands. Even if you wash your hands or use sanitizer after visiting public areas such as shops, or after using public transport, you still have to disinfect your personal high touch items as you may have touched and contaminated these objects before having properly cleaned your hands.

According to, high touch surfaces have been shown to play a role in the transmission of pathogens, both directly by surface-to-mouth contact and indirectly by contamination of hands and subsequent hand-to-mouth contact. Pathogens are bacteria, viruses or microorganisms that can cause disease, and these can stay on surfaces if they are not properly disinfected. The website mentions that viruses such as hepatitis A and rotavirus can survive up to one month on hard, non-porous surfaces, while noroviruses can survive up to 42 days on the same types of surfaces. The virus that causes COVID-19 can also survive on surfaces. The World Health Organization (WHO) states that recent studies suggest the virus can survive for up to 72 hours on plastic and stainless steel, less than 4 hours on copper, and less than 24 hours on cardboard. This depends on conditions (such as the type of surface, temperature or humidity of the environment).

Various research projects have been conducted on the bacterial content of some frequently touched items, and these can give us a good idea of just how dirty these objects can get:

Smart devices

Smart devices

We all use our smartphones constantly throughout the day. A survey by global tech care company  Asurion, estimated that the average American touches their phone 96 times a day.1  This means there are a number of opportunities for germs to be transferred to your smartphone.

A study by a leading German university (Hochschule Furtwangen University) analysed 60 smartphones for bacteria growth and 100% of phones that had not been cleaned showed evidence of bacterial presence on them in small concentrations.2  The research indicated that on an uncleaned 4 inch touch screen approximately 60 microorganisms were present. It is important to note that not all of these microorganisms were harmful and/or dangerous. However, the study does show that small numbers of some potentially dangerous bacteria, such as Escherichia coli were found on the touchscreens, and 50% of the bacteria identified belonged to Risk Group 2 meaning they were potential pathogens.

If this is true for smartphones, the same principle applies to tablets, smart watches, computer screens, keyboards and laptops. For this reason, it’s important to extend our good hygiene practices to include cleaning smart devices as well.

Eye glasses

Eye glasses

According to the American Academy of Ophthalmology, certain harmful pathogens, including the virus that causes COVID-19 can spread through the eyes just as it does through the nose and mouth. Although glasses and sunglasses don’t offer complete protection from saliva droplets that can carry pathogens, it may be an extra layer of defence. If you are prone to touching or rubbing your eyes, glasses can also prevent you from doing so, and prevent the transmission of germs between the hands and eyes.

Despite giving you a protective shield, however, your glasses are in an exposed position and in close contact with your skin, eyes, nose and mouth. You also have to put on and remove your glasses with your hands, which means they are handled frequently.

A research study investigated the bacterial content of worn spectacles and analysed the effect of using different cleaning methods. In this study all of the spectacles were found to be contaminated with bacteria.3

For this reason, you can assume that your lenses and frames potentially carry germs, and you should definitely disinfect glasses regularly with lens cleaner.

Bank cards

Bank cards

Banknotes and bank cards are also frequently touched items – and these items are exchanged between several people every day. As you’re not the only person handling your cash or card, be sure to wash or sanitize your hands after handling banknotes or coins, and to clean your credit card after it has been touched by store clerks.

It’s even easier to avoid handling these items altogether by using contactless payment methods such as tapping your card, or scanning a payment barcode with a phone payment application.

Car keys, wallets and handbags

Car keys, wallets and handbags

Think of your routine when visiting a grocery store or mall. When checking out your items, you’ll handle your wallet and handbag both before and after making a payment. The payment process usually involves touching banknotes or a credit card that has been handled by a store clerk. Afterwards, if you travel home by car, you then have to touch your car keys.

This involves a lot of touching and handling of various surfaces and items, which warrants hand washing or sanitizing and disinfecting the items afterwards.

The best cleaning methods for high touch items

The good news is that soap, alcohol-based hand sanitizer, and most regular household cleaning products can generally be used quite effectively to clean your hands and home.

Routine cleaning is the best way to minimise the spread of germs. Clean all high touch surfaces and items daily, and if it becomes visibly dirty, clean it straightaway.

Digital devices can easily be cleaned with pre-moistened wipes, designed for the purpose.

Digital devices can easily be cleaned with pre-moistened wipes, designed for the purpose.

How to clean your smart devices

Only wipe your smart devices with screen wipes that are specifically designed for the purpose, such as ZEISS Smartphone Wipes. The fast drying, alcohol free wipes are designed to remove fingerprints and dirt from your smartphone or other devices. Your smart device should be cleaned daily, or more frequently depending on the risk of exposure to germs. Check your device’s manufacturing information before you start.

Here’s how to clean ipad screens, mobile phones, smart watches and other digital devices:

  1. Remove the device from its case.
  2. Remove the folded ZEISS Smartphone Wipe from its packaging and lightly brush away dust and dirt from the screen with the folded wipe.
  3. Next unfold the wipe and begin to clean the screen and body of the phone/tablet or smartwatch using a circular motion. Ensure you clean all around the surface of the device.
  4. Charging points tend to accumulate a lot of dirt and grime. Use the wipes to clean the surface area around these points and then use a small brush, dry foam swab or a dry cotton bud to gently remove dirt from within this area.  
  5. Don’t forget to also clean the case, cover or sleeve based on its material. For the majority of plastic or hard cases warm water and soap is adequate. Wait for the case to dry completely before replacing your smart device inside it again.    
Glasses accumulate a lot of grime and dirt, and should be cleaned every day.

Glasses accumulate a lot of grime and dirt, and should be cleaned every day.

Good glasses hygiene

You should disinfect glasses at least once a day, and after you have been to a public space. If you work in an office with other people, aim to clean your glasses regularly.

The best way to clean your glasses is with lens cleaner such as a lens wipe or lens cleaning spray and a microfibre cloth. A recent study shows that cleaning lenses with a cellulose alcohol lens cleaning wipe can reduce dominant bacteria by up to 99-100%.3  Pre moistened wipes such as ZEISS Lens Wipes can effectively clean optical surfaces including coated lenses. The pre-moistened alcohol wipes are designed to leave a streak-free finish with no risk of scratching.

How to clean your glasses:

  1. With clean hands, open a sachet of ZEISS Lens Wipes, remove the wipe and unfold it.
  2. Gently hold your glasses by the frame.
  3. Using the folded wipe, gently wipe away any surface dust.
  4. Unfold the wipe and begin to clean the lens with circular movements until it’s clean.
  5. Store your glasses in a protective glasses case that is clean and free of dust.

Cleaning products to use for high touch items


Recommended cleaning product

Car keys

Household cleaning wipes or spray

Wallets, handbags and purses

Fabric items can be machine washed with other laundry and laundry detergent. Leather items can be wiped with a damp, soapy cloth. Faux leather can be wiped with alcohol wipes. (Always check the manufacturer label first)

Smart devices such as mobile phones, tablets, smart watches, laptops and computers

Smartphone wipes

Eye glasses

Low alcohol lens cleaning wipes

Drinks bottles

Machine wash or hand wash with dishwashing liquid

How to avoid foggy glasses when wearing a mask

Institutions such as the Centers for Disease Control recommend wearing face masks in public spaces to slow the spread of germs and diseases. But if you wear a face mask with glasses, this can be quite uncomfortable, and even stressful. When you breathe or speak, warm air escapes through the mask opening at the top, and your glasses fog up. If you don’t know how to avoid foggy glasses with a mask, you have to unnecessarily touch and handle your glasses, and you may end up contaminating them. Luckily there is a solution to the problem, and you can prevent foggy glasses when wearing a face mask.

How to avoid foggy glasses when wearing a mask

First of all, you need to ensure that your mask fits well, and that you put it on properly. With clean hands and before you enter a public space, fit the bendable metal strip tightly around your nose area. If you have a homemade cloth mask, you can use a pipe cleaner or soft wire stitched into the fabric to mould the mask around the lower part of your nose bridge. A proper fit will let less air escape and lessen the condensation on your lenses. However, the most effective way to prevent foggy glasses, is an anti fog spray or kit.

A boy wearing a mask with clear glasses
A boy wearing a mask with foggy glasses

How to prevent foggy glasses with face masks, using the ZEISS AntiFog kit:

  1. Clean your lenses with lens spray or cleansing wipes to remove any dust or dirt.
  2. Moisten the special anti fog cloth with one or two squirts of the anti fog spray.
  3. Rub the cloth on both sides of your lenses until the surface is evenly coated and completely dry.
  4. Apply a new coating of AntiFog every 72 hours to ensure optimal performance.

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  • 1

    Asurion-sponsored survey by Market Research Firm Solidea Solutions conducted August 18-20, 2019 of 1,998 U.S. Smartphone users, compared to an Asurion-sponsored survey conducted by market research company OnePoll between Sept. 11 – 19, 2017 of 2000 U.S. adults with a smartphone

  • 2

    Egert, Markus & Späth, Kerstin & Weik, Karoline & Kunzelmann, Heike & Horn, Christian & Kohl, Matthias & Blessing, Frithjof. (2014). Bacteria on smartphone touchscreens in a German university setting and evaluation of two popular cleaning methods using commercially available cleaning products. Folia microbiologica. 60. 10.1007/s12223-014-0350-2.

  • 3

    Birgit Fritz, Anne Jenner, Siegfried Wahl, Christian Lappe, Achim Zehender, Christian Horn, Frithjof Blessing, Matthias Kohl, Focke Ziemssen, Markus Egert. (2018). A view to a kill? – Ambient bacterial load of frames and lenses of spectacles and evaluation of different cleaning methods. PLoS ONE 13(11): e0207238.