Topic 1: Light and the Eye

In which lens condition is the light focused behind the eye?

• Emmetropia

• Myopia

• Hyperopia

• Astigmatism

What optical structure in the eye is responsible for the greatest refraction of light?

• Lens

• Aqueous humour

• Cornea

• Vitreous humour

The higher the refraction index, the greater the ______________ of a substance.

• Illuminance

• Density

• Mass

• Luminance

 

Which statement is true about rods and cones?

• Rods are not light sensitive; cones are light sensitive

• Cones have low acuity; rods have high acuity

• Rods respond to photons fast; cones respond to photons slow

• Rods are achromatic; cones are chromatic

Which of the following statements best describes why rods are so sensitive to light?

• One photon will elicit a cascade of events in the rod that will ultimately close millions of sodium channels

• The photopigment in rods, Rhodopsin, is extremely sensitive to light

• Because rods respond to fewer wavelengths, they can process photons more efficiently

• Rods are closer to the surface of the retina and therefore capture light photons before the cones