Question 1

Which property of light is important for understanding how it behaves when passing through small apertures? Light as

Accepted Answer

Light behaves like waves, which can diffract or bend when passing through small apertures. This is important to understand for applications such as optics and diffraction gratings.

Question 2

Which of the following statements about visual angle is not correct? Visual angle:

Accepted Answer

Visual angle is not the angle between the lines of sight of the two eyes; that description refers to binocular disparity or convergence angle. Visual angle actually refers to the angle subtended by an object at the eye, indicating how large the object appears to the observer, which can indeed be calculated using trigonometry and depends on both the size of the object and the distance from the observer.

Question 3

Optical power is expressed in which one of the following measures?

Accepted Answer

Optical power is typically expressed in dioptres, which is a unit of measurement used to quantify the refractive power of lenses or the ability of the eye to focus.

Question 4

Which term describes aged-related loss in accommodative range?

Accepted Answer

Presbyopia is the term used to describe the normal age-related loss of accommodative range, which makes it harder to focus on near objects. Presbyacusis refers to age-related hearing loss, while myopia and hyperopia are refractive errors that affect distance vision.

Question 5

The diameter of the pupil varies between approximately

Accepted Answer

The diameter of the pupil varies between 2-7 mm. This can change depending on factors like lighting conditions and emotions. In bright light, the pupil will constrict to a smaller size, while in low light, the pupil will dilate to a larger size.

Question 6

Which one of the following statements about rods and cones is not correct?

Accepted Answer

Rods outnumber cones in the human eye, with about 120 million rods compared to about 6 million cones.

Question 7

Which one of following terms correctly describes the jerky, rapid, eye movement used to shift eye direction?

Accepted Answer

Saccade is a type of eye movement where the eye rapidly changes direction to refocus on a new target. This movement is characterized by a quick, jerky motion and is used during reading, scanning, and other visual tasks that require frequent shifts in gaze direction. Pursuit movement refers to a smooth, tracking motion of the eye as it follows a moving object, while optokinetic nystagmus and vestibular-ocular movement are both related to maintaining visual stability during head movements.

Question 8

Which one of the following eye movements is triggered by head deceleration or acceleration?

Accepted Answer

Vestibular-ocular movement is triggered by head deceleration or acceleration. The vestibular system in the inner ear detects changes in head movement and sends signals to the oculomotor system, leading to compensatory eye movements that stabilize the visual field. Optokinetic nystagmus, vergence eye movements, and saccades are all involved in visual tracking and exploration, but they are not directly triggered by head movement.

Question 9

Binocular fixation on a point close to the observer requires:

Accepted Answer

Binocular fixation on a point close to the observer requires a large convergence angle to align the visual axes of the two eyes on the near target.

Question 10

Which one of the following is unlikely to result in a decrease in pupil size?

Accepted Answer

Scotopic light levels refer to very low light conditions, under which the pupils would dilate to allow more light in, not decrease in size. Entering a brightly lit room, normal aging, boredom, and divergence of the eyes are all conditions or actions that can lead to a decrease in pupil size.

Question 11

Who first proposed the theory of quantum mechanics, in which light is both a wave and a particle?

Accepted Answer

The answer of Who first proposed the theory of quantum...

Question 12

The function describing energy emitted by a light source as a function of wavelength is called its

Accepted Answer

The spectral power distribution describes the amount of energy emitted by a light source at each wavelength. The other options are not accurate descriptions of this function. Spectral reflectance function describes the amount of light reflected by a surface at each wavelength, color spectrum refers to the visible colors produced by a light source, and the illuminant function typically refers to the spectral power distribution of a standard light source used in color measurement.

Question 13

Ray properties of light are useful for:

Accepted Answer

The answer of Ray properties of light are useful for:
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Question 14

Which of the following is the range in which humans can typically detect wavelength?

Accepted Answer

The visible spectrum to the human eye ranges from approximately 400 to 700 nanometers (nm). This corresponds to the colors violet, blue, green, yellow, orange, and red.

Question 15

Which one of the following is the correct sequence of colours in the visible spectrum?

Accepted Answer

The correct sequence of colours in the visible spectrum is red-orange-yellow-green-blue-indigo-violet, which matches option D. Options A, B, and C have incorrect orders of the colors in the visible spectrum.

Question 16

Which of the following does not contribute to increased spatial resolution in the eye?

Accepted Answer

Long photoreceptor length does not contribute to increased spatial resolution in the eye. Instead, factors like small receptor spacing and small inter-receptor angles enhance spatial resolution by allowing the eye to distinguish between fine details. Long focal length is related to the optical system of the eye but does not directly contribute to the spatial resolution in the way that receptor characteristics do.

Question 17

To achieve a high level of sensitivity at low light levels is would be best to have:

Accepted Answer

Rod photoreceptors are more sensitive to light than cone photoreceptors and are responsible for vision in low light conditions. A large number of rod photoreceptors will increase sensitivity at low light levels.

Question 18

Which of the following is defined as a measure of relative luminance?

Accepted Answer

Contrast is defined as a measure of relative luminance.

Question 19

Luminous energy emitted by an extended light source is measure in which units?

Accepted Answer

Radiant flux is the measure of the total luminous energy emitted by a light source and is typically measured in watts. Candelas measure luminous intensity, which is the amount of light emitted in a specific direction. Trolands measure the retinal illuminance, which is the amount of light that enters the eye and is focused on the retina. Therefore, the correct answer is (C) radiant flux.

Quiz 6: The Physics of Vision & Light and the Eye