Lenses are either concave or convex. Concave lenses curve inward from both sides, and convex lenses curve outward one side and inward on the other. Concave and convex lenses change the image to be able to see from close or far distances.These are used for glasses, magnifying glasses, and telescopes.
If you are talking about lenses glasses. They help people see long distance or short
Hyperopic, plus powered, or convex lenses.
You can if you're using Extended contact lenses, these you can use for up to a month I believe as long as you clean them. You could reuse Daily contact lenses, but it's not recommended seeing as they are usually thrown away after their purpose has been served.
you shouldnt.
how long the doctor says
depends...
It means you you have a 100 power on your lenses - you cannot see long distances.
Thermal lenses are built with two lenses put together, which will (in most cases), eliminate fogging altogether. Although the downside is they tend to not last as long, and are more fragile than single lenses.
Camera lenses that enlarge distant images are normally known as long focus lenses or telephoto lenses. A few specialist lenses use mirrors as well as glass and are frequently referred to as mirror lenses.
long -sigtedness
convex lenses
Contact lenses that you can leave on for a long time are called extended wear lenses. These are the ones that you can wear to sleep. Some gas permeable lenses can be worn up to a month at a time.