Night & day contacts lenses have now been accepted by many consumers. However, the emergence of night day contact lenses does not come into being till recent years. Because, different from traditional lenses, night & day contact lenses are much difficult to produce. As for any manufacturers, they have to overcome some difficulties in producing night & day contact lenses. Following are some common items that are needed to be noticed when making night day contact lenses.
The problem of security should be put into first consideration when making night & day contact lenses. As it is known that night day contact lenses will stay in the eyes all-day-long, the safety of these products are of vital importance. And this is the overriding aspect when people decide to purchase them. Some special biomaterials have been invented and the problem of safety has been solved. Especially, some night & day contact lenses have won the approval of FDA, which is an authorized institution for safety appraisal.
All the night & day contact lenses should make the eyes of wearers always wet. In most cases, wearers find they are suffering from very serious eye dryness. One of the most important problems that night day contact lenses should solve is combating dryness. Because night day contact lenses will be worn during the night time, they must have high level of moisture. Only sufficient moisture can ascertain the eyes are always comfortable.
All the night & day contact lenses should let oxygen go through them. Oxygen is very important for the metabolism of eyes. Many designers of night & day contact lenses have used to try all their best to produce lenses with such functions. Now, some lenses are very typical, such as CIBA night vision night day contacts lenses, etc.
All the night & day contact lenses should resist eye allergy. Many people have very sensitive eyes, and they do not want to handle the lenses every day. Therefore, night day contact lenses are ideal choices. However, the lenses should first combat allergy itself. Of course, as for this problem, some night & day contact lenses, made from special materials, have been put into the market, so as to cater for people’s needs.