Question

What type of lens would you use as a magnifying glass ? How close must the object be to the lens ?

Answer 1

We use a reading glass generally to read small letters on the newspapers or textbooks or novels. When our eye muscles become weak, we have a problem in reading small letters. We cannot focus the images very well on the retina.

We use a convex lens or converging lenses for reading text. They magnify the size of the actual objects.

The object is placed within (less than) the focal length of the convex lens. So an enlarged virtual image is formed on the same side as the object. This virtual image is at around 25 cm from our eye. So we can see object clearly.