For contact lens users, you may be familiar with the term water content. But unfortunately, some people have wrong perception of this.
Water content level is often a reference in contact lenses selection. Many people think that higher water content lens is more moist and not easy to dry, but in fact that opinion is less precise.
Material properties
Softlens or soft contact lenses (non-silicone hydrogels) are made from Hydroxy-ethyl methacrylate or HEMA-abbreviated hydrogel hydrophilic (water loving). Just like a sponge that easily absorbs water, this material needs water to have perfect curvature and shape. For example, contact lenses with water content of 58% means contact lens material is only 42% while the rest is water. Softlens do not produce water, but need water. Where does softlens get water?
While still in the package, the water requirement is taken from the solution of immersion. But when used in the eye, softlens will take it away from our tears. This is what makes the eyes sometimes feel dry, especially at the end of usage.
High VS Low Water Content
Based on the Food and Drug Administration (FDA), water content of contact lenses is divided into 2, that are high water content (above 50%) and low water content (below 50%). Then which one is better, high or low water content? The answer depends on eye condition. If the quantity and quality of your tears are normal, better use a high-water softlens. Softlens with high water content can carry more oxygen to the eye.
But if you have a little tear production, it would be better to use a low-water softlens. Softlens with low water content will absorb less tears to keep the moisture.
Make sure you check the eye condition and health before buying contact lenses. A brief examination of eye health conditions is necessary to avoid the risk of complications. Discussion between contact lens practitioners and customers is also very useful to ensure the selected contact lenses are in accordance with the needs. Then you should find out about the most suitable contact lens for you, the product information, and useful tips before buying a contact lens.
(source: optikmelawai.com)
