The water content of a contact lens means exactly that – how much of the contact lens is made up of water. This figure is always given as a percentage.
Most contact lenses today are made from a soft plastic known as hydrogels. Hydrogels absorb a larger amount of water to keep the lens soft. The absorbing power of hydrogel material is also known as water content.
How can I find out the water content of my contact lenses?
Usually, you’ll be able to find the water content percentage displayed on the packaging of your contact lenses. Here, you’ll also see the components that make up the rest of the lens and which material forms the surface of the lens.
To find out the water content of your contact lenses, or the lenses you’re looking to buy, why not take a look at our contact lens specification table.
Does the water content percentage affect the comfort level of my lens?
A higher water content generally means a thicker lens, which can often be felt in the eye. Nowadays, mid water lenses, which are thinner and more widely worn, offer a greater degree of comfort to those who wear contacts. The general design of the lens and the smoothness of its edges will also have a major contributing factor to the comfort on the eye.
Is higher water content in contact lenses better for dry eyes?
High water content lenses, contrary to popular belief, are generally not the best for dry eyes. Contact lens wearers who are more prone to dry eye syndrome will find contact lenses with a lower water content more comfortable to wear.
With high water content lenses, the moisture in the lens draws out the eye's tears making them more prone to dehydration. High water contact lenses are also more likely to become dehydrated due to everyday environmental factors such as excessive screen use and air conditioning.
Silicon hydrogel contact lenses are a popular choice for those with more sensitive eyes as they allow more oxygen to pass through than lenses with a regular hydrogel surface. They also have a higher oxygen transmission which means that eyes will stay fresh and healthy throughout the day. The material of these lenses absorbs and locks in water, keeping your eyes hydrated so that they don't get dry as easily.
Some people refer to the oxygen permeability of contact lenses as the DK value. Gas permeable contact lenses are usually classified according to their DK value. These lenses do not contain a high water content.
Your optician will prescribe you the best lenses for your eyes, and if you have particularly dry eyes then you’ll most likely be prescribed mid water type lenses due to their versatility and comfort.
Following a good eye care routine can certainly benefit your eye health and if you suffer from dry eyes using eye drops will help to relieve you of any discomfort. Our comfi Drops work to rehydrate and lubricate your eyes throughout the whole day.
What should the water content be for contact lenses?
The amount of water in contact lenses varies depending on the type of lens. For those who wear soft contact lenses, the water content ranges between 38 to 75 percent.
Soft contact lenses are usually available in three categories: Low water content contact lenses containing less than 40 percent water, medium water content containing 50 to 60 percent water and high water content contact lenses containing more than 60 percent water.
What are soft contact lenses made of?
Soft contact lenses are made of soft, flexible plastics including a silicon hydrogel material which absorbs lots of water, keeping the lenses soft and supple. They are considered to be better for your eye health as they decrease the risks of hypoxia.
How dehydration impacts your eyes
A guide to dry eyes