It depends how long you wear your contact lenses. Usually, for people who were first time wearing contact lenses, they shall not wear it over 2 hours. Then, they can gradually increase the time of wearing contact lenses every time. But commonly, people are suggested that not wear contact lenses over 8 hours every time. So, i suggest you take your contact cases when you wearing contact lenses. When you feel discomfort in the eyes, you can take then off. If you have very poor vision, you shall prepare a pair of prescription glasses, too.
Yea, wearing contacts for a too long time is bad for your eyes. Contact lenses are designed to be worn on a monthly, bi-weekly, or daily schedule. When you wear the contacts over the recommended amount of time, the material of contacts begins to deteriorate. And the increasing amount of protein deposits on the lens will lead the lens to become cloudy and less clear. You know, oxygen transmission is critical for the health of the cornea. However, too long time wearing contacts will impede the oxygen transmission and deprive the cornea of oxygen, as a result of which corneal ulcer, corneal infiltrate, infection, corneal neovascularization, corneal edema would develop. Most of these problems are serious and can lead to loss of vision. Therefore, wear your contacts in the recommended amount of time.
Yes, it is quite harmful for you to wear the eye contacts for too long a time. The longest time to wear eye contacts every day is eight hours. And if people usually wear the contacts more than eight hours every day, they will easily get keratitis. This is because that the eye contacts are in direct touch with the cornea in the eyes. And the cornea is the passageway for the eyes to transport water, oxygen, and wastes of metabolism. Long time of wearing the eye contacts can to some extent hinder the normal operation of the cornea, and as time goes by, people may get keratitis. Therefore, the best way is to wear contacts for less than eight hours every day, less than five days a week.