Traditional glasses with frames can be used for three to five years or longer without considering human damage.But like contact lenses, they don't last that long.Contact lenses have a very strict shelf life because there are deposits that stick to the lenses during wear and they are difficult to remove completely.So, how long is this shelf life?
Contact lenses come with an expiry date on their packaging. This is the time from the moment the lenses are made to their complete failure.Most contact lenses are good for three to five years, as long as they are not opened in a sealed package.But if the date is exceeded, the contact lens cannot be used even if it is not opened.
So if we buy contact lenses used open and how to calculate the shelf life?Contact lenses have an important parameter called life cycle, with the longest one year and the shortest one day, which represents the maximum time the lens can be allowed to last.When we wear contact lenses, we must use and discard in strict accordance with the use cycle, and, in order to avoid wearing the eyes secreted proteins and other sediments adsorption on the lens to affect the oxygen permeability of contact lenses, contact lenses must be used every day after the use of nursing solution for cleaning care.However, with the increase in cleaning times, a lot of contact lenses are often not to shelf life will have lens hardening, transparency decline and other phenomena, should immediately stop using at this time.
对于隐形眼镜来说，保质期就是安全使用的基础，千万不能为了节省而超期使用，以免镜片被污染从而危害眼部健康。For contact lenses, shelf life is the basis of safe use, never in order to save time and use, lest the lens is contaminated thereby harm eye health.