Which of the following statements regarding visual pathways and visual fields is true?

Correct Answer: B

Rationale: The correct answer is B because the image formed on the retina is indeed upside down and reversed from its actual appearance in the outside world due to the way light rays are refracted and focused by the cornea and lens. This phenomenon is known as the inverted retinal image. Choice A is incorrect as visual pathways cross at the optic chiasm, so the right side of the brain interprets vision for the left visual field from both eyes. Choice C is incorrect as light rays are refracted at the cornea and lens, not through the transparent media of the eye before striking the pupil. Choice D is incorrect as light impulses are conducted through the optic nerve to the occipital lobes, not the temporal lobes, where the primary visual cortex is located.

Correct Answer: B

Rationale: The correct answer is B: the patient can read at 6.1 m (20 ft) what a person with normal vision can read at 9.1 m (30 ft). This is because the Snellen notation 20/30 means that the patient can read at 20 feet what a person with normal vision can read at 30 feet. This ratio signifies the patient's visual acuity compared to a person with normal vision. The other choices are incorrect as they do not accurately interpret the Snellen notation or misinterpret the distance at which the patient can read the eye chart.

Correct Answer: D

Rationale: The correct answer is D: A slight amount of lid lag when moving the eyes from a superior position to an inferior position. In the diagnostic positions test, when the eyes move from an extreme superior position to an inferior position, a slight amount of lid lag is expected due to the normal anatomical structure and mechanics of the eye muscles and eyelids. This lag is a normal finding and not indicative of any underlying pathology. Rationale: A: Convergence of vision in both eyes is not a normal finding in the diagnostic positions test as convergence refers to the inward movement of both eyes towards each other to maintain single binocular vision. B: Parallel movement of both eyes is not a specific finding in the diagnostic positions test. The test is designed to assess the movement of the eyes in different directions. C: Nystagmus in extreme superior gaze is not a normal finding and indicates an abnormality in eye movement coordination, not an expected finding in the diagnostic positions test.

Correct Answer: C

Rationale: The correct answer is C because shining a light across the pupil from the side allows for both direct (ipsilateral) and consensual (contralateral) pupillary constriction to be observed. This technique helps to assess the integrity of the cranial nerves involved in the pupillary light reflex (CN II and III). Direct constriction occurs in the eye exposed to the light, while consensual constriction occurs in the opposite eye. This comprehensive assessment ensures that both pupils are responding appropriately to light stimulation, providing a more accurate evaluation of the reflex. Choice A is incorrect because inspecting for pupillary constriction from directly in front may not adequately assess for consensual constriction in the opposite eye. Choice B is incorrect as asking the patient to follow the penlight in eight directions does not specifically target the pupillary light reflex. Choice D is incorrect as it focuses on accommodation rather than the pupillary light reflex.

Correct Answer: A

Rationale: The correct answer is A because fixating on an object at 2 weeks is within the expected developmental range. Infants typically develop the ability to follow objects later on. Choice B is incorrect as absence of following light doesn't indicate blindness. Choice C is unnecessary and premature. Choice D is incorrect as the ability to follow objects typically develops around 6-8 weeks.