जब श्वेत प्रकाश एक कांच के प्रिज्म से होकर गुजरता है, तो वह विक्षेपण के कारण कितने घटक रंगों में विभाजित हो जाता है?

A person can clearly see objects only at distances greater than 40 cm. Assuming the near point of a normal eye is 25 cm, what power of corrective lens should he be advised to use?

The power of accommodation of the human eye refers to the ability of the eye to: