These drops will help to moisten your eyes and give you some relief from the irritation that dryness causes. All in all, contact lenses are preferred over glasses. You ll need to change them out though, normally every couple of weeks. Changing them out with a fresh pair will make your eyes feel refreshed, and keep you from getting infections. As long as you clean and disinfect them on a regular basis, they will last you for quite a while. Without the supervision of a doctor, may doctors don t advise the use of non prescription contact lenses. Doctors will tell you that when they don t monitor the fitting, usage of the contacts, and the overall effects, they may cause you serious problems and possibly even blindness. Toric lenses are for those who have astigmatism, spherical is for short sightedness, and the correction of long sightedness, and multi-focal contact lenses are used in the correction of presbyopia. All three designs have their distinct purpose, and you should always ask your optician before you rush out and buy one. Although other types of Acuvue lenses now offer Hydroclear, the advance lenses were the first. Hydraclear is a break through in contact lens technology, perfect for those who have problems with their lenses drying out. This technology is considered to be among the best - and ideal for anyone who wants the best for their eyes. Contact lenses, as we all know, have many different uses. They are mainly used to correct vision, although they can also be used for those who have just had cataracts, especially if the natural lens around was removed. Contacts can also be used in the treatment of various eye diseases, and scars on the cornea that have been caused by infections or injury. Glasses and contact lenses can both correct astigmatism as well. If you have astigmatism, you can wear either glasses or contacts. Astigmatism is an odd cornea shape that impairs vision, common with older people. Although most people think that only glasses will correct this problem, contacts can fix the problem as well.