Presently, air pollution has been serious. Many people bring eye drops with them and I am no exception. However, recently the Consumer Council tested several eye drops that are sold in Hong Kong and found out that a number of them that were made in Japan contain a preservative that can cause discomfort in people who are allergic to preservatives. I didn't realize that something that was a preservative would turn out to be harmful. We need to pay more attention when choosing our products.