Deadline case / Contact lens case

Do you forget the deadline of your contact lenses frequently?
Many people have got headacch to remember the frequences of wearing contact lences, especially when nowadays people rely on weekly
and monthly disposable ones so much.
Wearing expired contact lens is harmful to our eyes, so we need a tool to help us mark the usages.
"Deadline case"can records the date on the back,that easily reminds users the
expiry date of the lenses when the date is going to due. And users can wisely know when to change new lense.