Water Content on Contact Lens - Have you known that the selection of contact lens type we use is very important? Aside from the colors and patterns of contact lens which allow us to look more beautiful, we also have to choose a contact lens based on the quality and composition of the basic materials. We often chooses soft lens by seeing the physical beauty of the form without regard to the basic composition of the contact lens. Of course the mistake of selecting contact lens can be fatal for our eye health if our eyes are sensitive eyes. The most important things that need to be considered when selecting contact lens are water content, diameter, and thickness (base curve). These things relate to contact lens ability to absorb water and its ability to deliver oxygen to our eyes.

Water Content on Contact Lens

Let us understand what the meaning of water content on Contact Lens is, so that we can answer whether the good softlens has high water content or not. The background that explains how the material for contact lenses discovered has been discussed in previous articles (READ ALSO: Soft lens Creator, Benefits and Its Manufacturing).  

Contact lenses are generally made from soft hydrophilic material or plastics called hydrogels. The hydrogel material absorbs large amounts of water from the surrounding areas to keep the lens in order to stay soft and supple. The size of the absorbing power of hydrogel material is often known as water content. Contact lenses themselves are made as flexible as possible in order to make it comfortable to wear. Hydrogel used as the basic material for making soft lenses because until now hydrogel material is the most ideal material for the contact lenses manufacturing.  

Hydrogel Material

Water content standard on hydrogel material that is good for making contact lenses and comfortable to wear in the eye ranges between 38 to 75 % of the overall weight of the contact lens. Based on its water content, hydrogel is generally available in the following categories :  

• The water content is low (less than 40% of water absorbed)
• The water content is medium (50-60% of water absorbed)
• The water content is high (over 60%)

Thus we can say that the water content indicated on softlens we use is a measure of the soft lens ability to absorb water in the surrounding areas. So, the higher water content of soft lens means the higher absorptive capacity.   Nowadays, various brands of soft lens have different water content and thickness. Generally, hydrogel which has low water content have thinness that is thinner than a contact lens which has high water content.   During using contact lens, the water content of contact lens provides the pores of oxygen to pass through the lens and gives oxygen to the cornea. If we wear contact lens, the pores of contact lens will absorb our tears to maintain the flexibility. The amount of tears that is absorbed depends on the size and number of contact lens pores. The pore size is related to the water content information.

The higher water content has the larger absorption pores. Hydrophilic Material is Similar to a Sponge   It should be stressed once again, that softlens made of hydrophilic polymer materials, i.e. materials that can absorb water, whereas the original material doesn’t contain water. That means that soft lens have pores that will absorb the liquid from the place where it is placed. It can be said that the material is like sponge / foam. So the percentage of water content contained in the contact lens product packaging shows the percentage size of the contact lens in absorbing water in the surrounding areas, NOT the amount of water contained in the contact lens.  

After seeing the explanation above, we may wonder about something. If the water content has higher water content, is it means that our eyes will dry so fast? Then whether it is harmful to our eyes? The answer is, of course it is dangerous. It said the danger if the condition of our eyes is really dries, so it will cause eye irritation. Well, if it is dangerous, why high water content soft lens still be sold?   Keep in mind that the contact lens which is used is not really stick to the cornea of the eye, but floating in the tears that coats the cornea. The tears layer will continue to form / renew each time the eye blinks. Soft installed ideally if they can be moved as far as ± 1 mm each time the eye blinks. It is intended to make the tears layer can be renewed continually. If the contact lens with different water content used in the same eye, soft lens with lower water content will be easier to move/shift than the soft lens with higher water content. It means that soft lens with lower water content will have laxer condition than soft lens with higher water content.   Contact lenses are made with a water content varies due to differences between eye’s condition of each person.

There are likely to have excess tears, normal, and some are likely to be less. If contact lens with low water content is used in the eyes which produce excess tears, then Contact Lens conditions will be too lax, so the motion becomes redundant and easily dislodged. If soft lens with high water content is used in the eyes which produce less tears, soft lens conditions would be too stringent. Such conditions can lead to a shortage of oxygen in cornea, or often called hypoxia. It will cause the appearance of blood vessels in the cornea. It really should not happen.  

Besides all of that, as long as the water content of contact lenses within certain limits which have been mentioned above, soft lens is still safe to use. The water content in that range has been approved by the FDA. For example is soft lens sold in Softlens Queen. Differences in water content of that range just feel a little, it also may be felt after the long term use. Except, if you are accustomed wearing soft lens with lower content water, then suddenly use soft lens with higher water content, or vice versa, then it will feel a significant difference. Surely you can instantly tell the difference. Nevertheless soft lens is still safe to use.   The fact that we often encounter in addition to the facts above, the size of the water content is often linked to the size of the contact lens thickness, judging by the response of soft lens wearer.

Some contact lens wearer more comfortable with soft lens which is thin (low water content), on the other hand the wearer more comfortable to wear thicker soft lens with high water content.   Well, which one you like to choose? Both of these options are fine for giving a sense of comfort when wearing them. According to me, you can try both of them to know which one that fit with your eyes.   Those are the information about water content on contact lens. Hopefully the information above will be useful for you.