No matter how well you know the person, you should never switch contacts with them. Swapping contacts can damage your eyes, in the terms of protein and contact shape/power. Anytime your eyes start to bother you, you should take your contacts out and allow your eyes time to rest. Normally, if your contacts are causing irritation, allowing your eyes ample time to rest will correct the problem. Contact lenses are designed to correct your vision and often times protect your eyes, which is why you want to choose them carefully. If you pick your contact lenses carefully, you ll get the best type for your eyes. Your optician will give you his recommendations during your fitting exam, and go over how you should care for your new contacts. They are good up to a month per pair, which makes them ideal for everyday use. They normally come in boxes of 6, meaning that a single pair will last you up to 3 months. If you wear contacts, you should look into the Acuvue advance. You can buy them online, through your local optician, or anywhere else that sells contacts. In definition, presbyopia is the lack of focusing on things in close range. The cause for this, is the lens in our eyes becoming less and less flexible as we grow older. The bad part is, most of us will need some type of corrective lenses, such as contact lenses or glasses and possibly even bifocals at some point in our lives as this condition gets worse. They also offer you a full field of vision as well, which is great for sports. The lens and focus is the same as glass, meaning that you will get the same vision from contacts as you would with a pair of glasses. A lot of people who have vision problems consider getting Lasik eye surgery to fix their vision problems so that they won t have to wear glasses or contacts. The first difference in the two is the field of vision. Glasses offer good front vision, although their peripheral vision is quite poor. Contact lenses on the other hand offer you a great field of vision, including peripheral. You won t be hindered to just looking straight ahead, as contact lenses allow you to look anywhere you want without any problems.