Contact Lenses Care

These lenses offer a unique blend of the advantages of both hard and soft lenses. They provide excellent visual acuity, and correct most types of astigmatism better than soft lenses (but not quite as well as conventional hard lenses). The gas-permeable lenses correct astigmatism in the same manner as the hard lenses by forming a perfectly round, smooth inner surface filled with tears. Multifocal gas-permeable lenses are also available for the presbyope. They are almost as durable as hard lenses, and much more so than soft lenses. You can expect gas-permeable lenses to last up to five years. Since the lenses are firm in consistency, they are handled easily and with greater confidence than are soft lenses. They can be accurately reproduced, so there are none of the surprises that can occur when reordering a soft lens. Read the rest of this entry »

This type of contact lens fills the need for many people who— for one reason or another—are not suitable for conventional hard or soft lenses. This is the lens for you if you:

Have found hard lenses uncomfortable, but are unwilling to give up their sharp visual acuity.

• Would like a contact lens that approaches soft-lens comfort, but cannot wear soft lenses because of astigmatism or “dry eye.”
• Like the idea of increased wearing time, but cannot wear soft lenses.
• Can’t handle soft lenses.

• Can wear soft lenses but don’t like the inconvenience involved in the care.
• Are interested in the possibilities of part-time lens wear, but can’t wear soft lenses.

Gas-permeable contact lenses are also known as oxygen permeable, semisoft, semihard, semirigid, or flexible lenses. As their names suggest, they are more flexible than conventional hard lenses, but less pliable than soft ones; and they are made from materials that allow oxygen and the waste gas carbon dioxide to pass through them. When the cornea can “breathe,” it experiences no edema (swelling), which causes discomfort, and there is very little distortion of the vision after the lenses are removed (spectacle blur). The eye remains healthier, even when the lenses are worn for long periods of time. Contrast this with conventional hard (PMMA) lenses, which allow virtually no oxygen to pass through them, and with soft lenses, which allow some oxygen to pass through via the tears they absorb (but less oxygen than passes through gas-permeable material via the atmosphere). Read the rest of this entry »