For contact lenses, expiration dates is very important. A number of studies have shown that the longer the contact lenses are used, the greater the probability of eye problems, especially when they are used over time, and the incalculable damage will be caused to the eyes after the performance of the lenses declines.
Before the contact lens is unsealed for use, we can judge whether it is expired according to the production date and shelf life marked on the package. Generally speaking, the shelf life of unsealed contact lenses is three to five years. Before expiration, contact lenses can be used normally.
After unpacking, the shelf life of contact lenses will be calculated from the same day. According to the different use cycle, we divide the contact lenses into daily,monthly,semi-annual,and so on. Among them, only the daily throwing contact lenses are special and belong to disposable products, and even if the daily throwing contact lenses are not used after unpacking, they will be considered to have passed the shelf life by the next day and can not be continued to wear.
Other types of discards are easier to understand. Shelf life is the life cycle of the tag. However, it is recommended that you discard them as early as possible, such as five days in advance for a month, one month in advance for a half year, and so on. Because the wearer can not detect many problems caused by lens aging in time, some slight corneal damage is ignored, which delays the treatment and leads to more serious consequences.
When purchasing contact lenses, it is seldom to encounter expired products. If it is found that the contact lenses have exceeded the expiration date, it is necessary to find a merchant to replace them in time. Once it is used, it is necessary to mark the date of unsealing and wear it in strict accordance with the use cycle.