CPO Basic Science 1 — Questions and Answers
Question 1: Which part of the eye is responsible for focusing light onto the retina?
- Cornea (Correct answer)
- Retina
- Iris
- Lens
Correct answer: Cornea
The cornea is the transparent, outermost layer of the eye that covers the iris, pupil, and anterior chamber. It plays a crucial role in focusing light onto the retina by providing the majority of the eye's refractive power, bending light rays as they enter the eye.
Question 2: What is the primary function of the retina?
- Regulate the amount of light entering the eye
- Convert light into electrical signals (Correct answer)
- Maintain the shape of the eyeball
- Provide nutrients to the eye
Correct answer: Convert light into electrical signals
The primary function of the retina is to convert light into electrical signals that the brain can interpret as images. It contains millions of photoreceptor cells (rods and cones) that detect light and color, initiating the neural pathway for vision.
Question 3: Which photoreceptor is primarily responsible for night vision?
- Cones
- Rods (Correct answer)
- Ganglion cells
- Bipolar cells
Correct answer: Rods
Rods are the photoreceptor cells in the retina primarily responsible for night vision and vision in dim light conditions. They are highly sensitive to light intensity but do not detect color, providing black-and-white vision and peripheral vision.
Question 4: What is the aqueous humor, and where is it located?
- A gel-like substance in the posterior segment of the eye
- A fluid in the anterior and posterior chambers of the eye (Correct answer)
- The clear layer covering the sclera
- A muscle controlling pupil size
Correct answer: A fluid in the anterior and posterior chambers of the eye
The aqueous humor is a clear, watery fluid located in the anterior and posterior chambers of the eye. It nourishes the avascular structures of the eye, such as the cornea and lens, and helps maintain the intraocular pressure, which keeps the eyeball inflated.
Question 5: Which structure controls the size of the pupil?
- Iris (Correct answer)
- Ciliary body
- Cornea
- Retina
Correct answer: Iris
The iris is the colored part of the eye that surrounds the pupil and contains muscles that control its size. By dilating or constricting the pupil, the iris regulates the amount of light entering the eye, adapting to different lighting conditions.
CPO Basic Science 1
Which part of the eye is responsible for focusing light onto the retina?