contestada

A person has a far point of 50 cm. If he is wearing glasses 2 cm from the eyes, determine
the power of the lens needed for him to see distant object clearly.​

Respuesta :

Answer:

The power will be "2.08 D".

Explanation:

According to the question,

The location of the image form lens,

[tex]d_i=50-2[/tex]

    [tex]=48 \ cm[/tex]

We know that,

⇒ [tex]\frac{1}{d_i} -\frac{1}{d_o} =\frac{1}{f}[/tex]

here,

[tex]d_o[/tex] = Object location

[tex]d_i[/tex] = Image location

[tex]f[/tex] = Focal length

On putting the values in the above expression, we get

⇒ [tex]\frac{1}{48} -\frac{1}{\infty} =\frac{1}{f}[/tex]

             [tex]f=48 \ cm[/tex]  

or,

             [tex]f=0.48 \ m[/tex]

hence,

The refractive power will be:

⇒ [tex]P=\frac{1}{f}[/tex]

       [tex]=\frac{1}{0.48}[/tex]

       [tex]=2.08 \ D[/tex]