What Does Water Content in Contact Lenses Mean?

What does water content in contact lenses mean? Water content is a crucial feature of the different plastics used to make soft contact lenses.

Meaning of Water Content in Contact Lenses

As a rule with conventional soft contact lenses, the greater the water content, the more oxygen can pass through the lens. This is very important for lens convenience and healthy eyes – but high water content lenses may be more fragile, so are most likely to tear with frequent handling.

The relationship in between water content and oxygen transmission is not the very same with lenses made from silicone hydrogel materials which attain really high levels of oxygen transmission no matter their water content.

Question About Water Content in Soft Contacts

I check out that disposable contact lenses are actually worse for your eyes than the normal 1 year ones since they permit less oxygen to go to your eyes, and the only advantage is that there are less cleansing issues. Likewise, it is claimed that insufficient oxygen to your eyes (possibly triggered by extended wearing of contact lenses) results in a condition when extra capillary grow around the iris, which results in sight issues at old age. Is that true?

I am really worried since I normally use (one-year) contact lenses from 8am to 8pm, and maybe to 12am during reading periods. I do not feel very comfy with glasses since they offer distorted visions and tiredness. I believed switching to non reusable contact lenses would do my eyes good. My present lenses include 38 percent water. Is this good enough?

Answer

As an option to prescription glasses, contact lenses not only proper vision, however likewise allow for peripheral vision, clear vision in the rain, fog-free vision in steamy locations, and vision without dirt splatters on a muddy bike flight. Contact lenses have actually evolved over 50 years, and now are typically offered and available at a relatively reasonable cost. In addition, lots of insurer cover contact lenses, in addition to prescription glasses.

But contacts do have their drawbacks. They can dry out your eyes, minimize oxygen to your cornea, get cloudy from protein deposits, and make your eyes more vulnerable to fungal and bacterial infection. The cornea is the just living tissue on the human body that gets its oxygen from the air rather than from your bloodstream. This suggests it likewise should launch co2 without the aid of blood. You are appropriate: When the cornea can not access sufficient oxygen from the air, it can go through a procedure of “neovascularization” in which it grows blood vessels to make up for the absence of oxygen. And forming capillary with time hinders vision since the cornea loses a few of its transparency if blood vessels are formed.

But don’t panic yet. You ask if 38 percent water content suffices. The answer is not so cut and “dry” unfortunately, but 38 percent is most likely fine if you have not been experiencing any pain or vision issues. Higher water content lenses are potentially beneficial due to the fact that more water indicates more oxygen to the eye– high water content lenses enable more oxygen into the eye (and more release of CO2) due to the fact that the water functions as a vehicle for the gases. But higher water content lenses have the tendency to also be more vulnerable (since they have less plastic) so manufacturers have the tendency to make them thicker than low water content lenses so that they will not rip as quickly. Ironically, this thickening of the lens neutralizes the benefit of more water!

Which kind of lense is “much better” likewise depends somewhat on the product of the lens. For instance, proof so far shows that silicone hydrogel lenses (e.g. CIBA Vision Night and Day) are quite healthy for the cornea, minimizing the probability for infection and keeping the eye fairly moist and oxygenated (since silicone is permeable to oxygen). But everyone’s eyes are different. For some people, 38 percent water content will be simply great and for others, it won’t suffice. Some people can wear CIBA Vision Night and Day contacts over night for 30 days while other individuals will never be able to sleep in contact lenses overnight without having issues (dry eye, infection, not enough oxygen, and so on).

You also inquire about extended wear versus disposables. Currently, proof does not seem to indicate that a person is healthier than the other. But it is a smart idea sometimes to alter out your contact lens case, in any case. In basic, if you feel good, look good, and see well while wearing the lenses, then you’re probably alright.

If all these conditions are satisfied, you’re most likely all right. But it’s good to keep in mind that numerous studies checking the results of lenses on the cornea and the eye as a whole are performed by contact lens producers and hence may be prejudiced. So make certain to talk to your health care service provider about your lenses; when they ask, be truthful about the length of time that you wear them. Inquire about the type of soaking and washing solution(s) you are using to make sure the solution is okay to use with the chemistry of your specific lens. Have re-wetting drops on hand to use if your eyes feel dry or get cloudy. And remember that even if a maker states you can wear your lenses for 12 hours, 24 hours, or 30 days without a problem, if your eyes are not happy, provide a break and use glasses for a bit.