Why do goggles fog up?

Besides condensation of water, contaminants like oils, lotions and sunscreens in the water can also unhelpfully aid in fogging-up your goggles.

Goggles are protective eyewear and an important part of swimming gear. Apart from protecting the eyes, they help to improve and maintain underwater visibility. When water touches the naked lens of the eyes visibility becomes blurred and distorted. Furthermore, water causes irritation to the eyes.

How do goggles fog up?

The answer is in humidity and temperature differentials. Fogging of goggles is caused when the outside of the lens are cooled by water while the inside is warmed by our body temperature. The resultant difference in temperature causes moisture droplets to form on the lens. Additionally, when the part of the face is covered up by goggles, the skin temperature rise considerably and which then causes perspiration. This evaporates and is transferred to the inside of the goggle lens. These droplet vapours are so fine they can hardly be seen by the naked eye but they act to scatter and diffuse light. This natural reaction is what causes fogging.

The same effect is seen on glass screens of cars when one is driving in the rain. To counter this, the demister was introduced as an anti-fogging agent. Likewise, when cold water is poured into a glass, droplets soon form on the outer surface. However with swimming goggles, there are other causes that unhelpfully aid in fogging up your goggles. Primary of all is contamination of the lens surface by lotions, oils and other contaminants in the water. These are responsible for impairing the function of anti-fog coatings especially on the inner side of the lens and prevent even anti-fog goggles from functioning efficiently. As a recommendation, swim caps should be worn in the pool to curtail contaminating of oils from the hair into the water.

What’s the remedy?

Anti-fog treatments were first developed by NASA in the 1960s. They function by preventing the condensation of water which causes fogging on the surface of glass or transparent plastics. The technology has since been applied to optical applications ranging from lenses, goggles, camera lenses, binoculars etc. Generally, anti-fog agents used in the treatment of goggles include surfactants which significantly reduce the surface tension when they come in contact with water. Other technologies include the use of hydrophilic coatings which maximize the surface energy, titanium dioxide and also hydrophilic nanoparticles and colloids. They create a film that helps to reduce surface tension and absorb moisture. Apart from these technological breakthroughs, numerous home remedies have also evolved. Though not recommended, spitting and licking on goggle lenses are done.

One of the best anti-fog treatment cleansing solutions you can get comes from View by Tabata, Japan. Tabata is a household name in swimming, snorkelling and diving gear and accessories. The four key features in the cleansing solutions are their non-irritating, long-lasting, high-viscosity and easy-to-apply properties. TV 331 and TV 330A anti-fog treatment cleansers are highly-effective for removal of oils and other contaminants from the lens. The cleansers also help to remove charged particles and restore the anti-fog goggles to pristine condition. These are common contaminants that impair anti-fog function.

It’s important to note that these cleansers work only on pre-treated anti-fog lens and not on regular or poorly made lenses. With poorly made lenses, you will also find that the inner side coat films peel off like damage skin. This condition doesn’t occur in Tabata VIEW anti-fog goggles since they are made to last. Tip: dry inner surface of goggle lens sustain fog-free performance far longer than dipping the goggle into water before a swim.

With anti-fog factory coating of lenses, the VIEW process undergoes rigorous processing. This starts from a contamination-free environment where the clean-room is free from dust and other atmospheric contaminants. An anti-fog coating is then delicately applied and the lens goes through a high-tech baking process. The finished lens is durable with the coating not easily eroded and not easily succumbed to scratches too.

How to apply anti-fog cleanser solutions?

It is noteworthy to remember that proper application of anti-fog cleanser solutions is important to ensure maximal function. A simple method is to spray the solution on the surface of the lens. Clean the lens with a soft tissue. Repeat this process and using your fingers, spread the liquid solution around. Give the lens a final wipe with the same tissue. To prevent careless scratching, do not rub the cleansing lotion vigorously on goggle lenses.

To see if the solution works, this is a simple test conducted by many. Place the treated lens in a freezer for about a minute and then remove them. Check for fogging on the lens.