Question

The increase in a object's apperent size is called

Answer 1

You know that our eye is an convex lens.

Now let

2F:-center of curvature

F:- focus

u:-distance of object from lens

v:- distance of image from lens

When object is very  away from eye then image form is too small. As we move it towarde eye it's size increases . and at u<F the image is very large.  

If I:- size of image

O:- size of object

Then longitudinal magnification is given as

m= I       =v2 -v1  

    O       u2 - u