a person needs a lens of power -5.5 dioptress for correct ing his near...
a person needs a lens of power -5.5 dioptress for correct ing his near...
The focal length of a lens can be calculated using the formula:
\( \text{Focal length (f)} = \frac{1}{\text{Power (P)}} \)
Where:
- Focal length (f) is measured in meters
- Power (P) is measured in diopters
### 1. Distinct Vision:
Given that the person needs a lens of power -5.5 diopters for correcting their distinct vision, the focal length of the lens required would be:
\( f = \frac{1}{-5.5} = -0.1818 \text{m} \)
The focal length for correcting distinct vision would be -0.1818 meters.
### 2. Near Vision:
For near vision correction, the person needs a lens of power +1.5 diopters. Using the formula mentioned above, the focal length of the lens required for correcting near vision would be:
\( f = \frac{1}{1.5} = 0.6667 \text{m} \)
The focal length for correcting near vision would be 0.6667 meters.
Therefore, the focal length of the lens required for correcting distinct vision is -0.1818 meters, and for near vision, it is 0.6667 meters.