Differentiate between.

  1. Convex and concave lens
  2. Virtual images and real images
  3. Myopia and hypermetropia
  4. Far point and near point

a. Convex and concave lens.

It is thick in the middle and thin at the edges.It is thin in the middle and thick at the edges.
It converges the parallel beam of light.It diverges the parallel beam of light.
It has a real focus.It has a virtual focus.
It has +ve power.It has -ve power.

b. Virtual image and real image.

It cannot be cast on the screen.I can be cast on the screen.
It is always erect.It is always inverted.
It is formed by the apparent intersection of rays at a point.It is formed by the actual intersection of rays at a point.

c. Myopia and hypermetropia.

It is the defect of vision in which a person can see nearby objects but cannot see distant objects.It is the defect of vision in which a person can see distant objects but cannot see nearby objects.
It is also called short-sightedness.It is also called long-sightedness.
It is corrected by using a concave lens.It is corrected by using a convex lens.

d. Far point and near point.

Far pointNear point
The distant point from the eye which can be seen clearly is called the far point.The nearest point which an eye can see the object clearly is called the near point.
The far point is at infinity for a normal eye.The near point is at 25 cm for a normal eye.