Which part of the eye contributes the greatest refractive power?
Answer
Cornea
The correct answer is Cornea — Therefore the component with the greatest power is the cornea.
Step-by-step solution
- Identify the refractive powers of the eye components.
- Cornea has a refractive power of about +43 dioptres, which is higher than the lens (+20 D) and the humours (+0.5 D).
- Therefore the component with the greatest power is the cornea.
Common mistake: Choosing the lens because it is thick and adjustable.
Concept tested: Refractive power of eye components
Published · How this solution was prepared and checked
Related questions
- 1 A person with a myopic eye can see clearly up to a distance of 1.2 m. What is the nature and power of the lens required to correct this defect of vision?
- 2 A myopic person sees distant objects clearly only up to a far point of 50 cm. What is the minimum power of a lens (in dioptres) required to correct his vision so that he can see objects at infinity clearly? Assume a thin lens placed close to the eye.
- 3 Which of the following statements correctly describes the changes that occur in the eye during accommodation for a near object?
- 4 Describe what happens to the ciliary muscle, suspensory ligaments and the shape of the lens when the eye focuses on a near object.
- 5 A hyperopic person can see distant objects clearly but cannot read a newspaper held at 25 cm without glasses. The far point of his eye is at infinity. Calculate the minimum power (in dioptres) of a thin converging lens that should be placed close to the eye to enable him to read at 25 cm.
- 6 A monochromatic red light (λ = 600 nm) and violet light (λ = 400 nm) pass through a prism whose apex angle is 30°. The refractive index of the prism for red light is 1.50 and for violet light is 1.55. Assuming small angles, calculate the angular dispersion between the red and violet rays after emerging from the prism.