* has limited usage (you can't see things that has long distance)
* It is not suitable for working, because it needs a hand.
advantage
* Magnifying glasses mounted in reading devices that can magnify print from three to 10 times its normal size are also useful for people who have eye diseases like rod and cone deficiencies or retinitis pigmentosa.
* Allow you to work closer. This is because a magnifier reduces the focal length of your sight.
* It will show up defects that eyes cannot see.
* Cheap and portable.