Author Question: You are designing contact lenses for someone whose near point is 43 cm. What focal length lens ... (Read 52 times)

stevenposner

  • Hero Member
  • *****
  • Posts: 608
You are designing contact lenses for someone whose near point is 43 cm. What focal length lens should you prescribe so that an object can be clearly seen when placed at 25 cm in front of the eye?
 a. 43 cm
  c. -15 cm
  b. 18 cm
  d. 60 cm

Question 2

A lens with a focal length of 12 cm has what refractive power?
 a. 5.0 diopters
  c. 6.7 diopters
  b. 9.6 diopters
  d. 8.3 diopters



Anton

  • Sr. Member
  • ****
  • Posts: 302
Answer to Question 1

D

Answer to Question 2

D



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

Though “Krazy Glue” or “Super Glue” has the ability to seal small wounds, it is not recommended for this purpose since it contains many substances that should not enter the body through the skin, and may be harmful.

Did you know?

Tobacco depletes the body of vitamins A, C, and E, which can result in any of the following: dry hair, dry skin, dry eyes, poor growth, night blindness, abscesses, insomnia, fatigue, reproductive system problems, sinusitis, pneumonia, frequent respiratory problems, skin disorders, weight loss, rickets, osteomalacia, nervousness, muscle spasms, leg cramps, extremity numbness, bone malformations, decayed teeth, difficulty in walking, irritability, restlessness, profuse sweating, increased uric acid (gout), joint damage, damaged red blood cells, destruction of nerves, infertility, miscarriage, and many types of cancer.

Did you know?

Side effects from substance abuse include nausea, dehydration, reduced productivitiy, and dependence. Though these effects usually worsen over time, the constant need for the substance often overcomes rational thinking.

Did you know?

In the United States, an estimated 50 million unnecessary antibiotics are prescribed for viral respiratory infections.

Did you know?

Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.

For a complete list of videos, visit our video library