Near sightedness and far sightedness happen when light is not focussed on the __________.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Concepts**:
- Nearsightedness (myopia) and farsightedness (hyperopia) are vision problems that occur when light does not focus correctly in the eye.

2. **Identifying the Key Component**:
- The retina is the part of the eye that acts like a screen where light is focused. It contains light-sensitive cells that convert light into electrical signals for the brain.

...