contact lens choices Your Contact Lens Choices Soft lenses are much more comfortable than rigid lenses, thanks to their ability to conform to the eye and absorb and hold water. You can get used to soft lenses within days, compared with several weeks for rigid contact lenses. An added benefit is that soft lenses aren't as likely as rigid lenses to pop out or capture foreign material like dust underneath. Extra-thin soft contact lenses are available for very sensitive people. While the ability to hold water increases oxygen permeability of soft contact lenses, it increases their fragility as well. Rigid lenses generally give clearer vision. They can be marked to show which lens is for which eye. They don't rip or tear, so they're easy to handle. Rigid contact lenses don't absorb chemicals, unlike soft lenses, which are like sponges.  soft lenses will suck up any residues from your hands, including soap, lotion, dirt, dust or grime.  Proper hand washing is critical to handling of soft contact lenses. Both soft and rigid lenses offer bifocal correction.  In some models, each lens corrects for near and distance vision.  In others, one lens is for near vision, and the other is for distance. Some people who have good distance vision but need help for reading can get a monovision reading lens for one eye.  Soft contact lenses additionally come as disposable products (defined by FDA as used once and discarded) or as planned replacement contact lenses. With planned-replacement lenses, the eye doctor works out a replacement schedule tailored to each patient's needs.  For patients who produce a higher level of protein in their eyes or don't take as good care of their lenses, it might be healthier to replace the contact lenses more frequently.  Check with your own doctor. Some doctors prescribe disposables as planned-replacement contact lenses, which are removed, disinfected and reused before being discarded.  Lenses labeled "disposable" don't come with instructions for cleaning and disinfecting, while those labeled specifically for planned replacement do. Whatever lenses your doctor prescribes, be sure to ask for written instructions for maintenance and follow them carefully. Very few people wear hard lenses any more, but they are available for people who have adapted to them and want them.  Hard  contact lenses are not the same as rigid gas-permeable lenses, since they do not allow oxygen transmission through the lens. Contacts Not for Everyone People with inadequate tearing (dry eye syndrome) usually can't tolerate contacts.  Severe nearsightedness often can't be corrected effectively with contact lenses. Certain working conditions and environments, such as exposure to chemical fumes, may be undesirable for contact lens wearers.  Contacts may be ruled out by allergy to lens-care products or by corneal problems, such as a history of viral infection of the cornea.  Extra caution should be exercised with diabetics, because they're susceptible to infection and have trouble healing. Cosmetic use of contacts is generally limited in children.  Adolescence is the youngest age as a rule to consider contact lenses.  Some doctors do prescribe contacts to ages 9 to 11 year olds. Contacts are usually prescribed for a younger child who has the motor skills and responsibility to handle the contact lenses. For some people who haven't been able to wear contacts and want to, implantable lenses may be an option. Doctors are studying ring segments, shaped like parentheses, which are implanted in the cornea. They flatten out the cornea, changing the shape to give the correct optical power.  Lenses that are implanted inside the eye are also being studied to correct refractive error. Correcting vision is not the only use for contact lenses. Some soft contacts are used as bandage lenses after photorefractive keratectomy laser surgery for nearsightedness. The surgery removes the outer cell layer of the cornea, creating a large abrasion on the eye. It's very painful if you don't have a protective covering on the cornea after the anesthetic wears off. Collagen eye shields are used as bandage lenses to relieve pain from other abrasions or sores on the cornea. They dissolve in a couple of days.