Human Eye — Set 1
Physics · मानव नेत्र · Questions 1–10 of 60
Which part of the human eye gives it its visible color?
Correct Answer: B. Iris
The iris is the colored ring around the pupil. Its pigments determine the visible eye color. The iris muscles also help regulate incoming light.
The image formed on the retina of a normal human eye is generally?
Correct Answer: B. Real, inverted, diminished
The eye lens forms a real image on the retina. This image is inverted because a convex lens inverts images. It is usually smaller than the object for normal viewing distances.
Which photoreceptor cells are mainly responsible for vision in dim light?
Correct Answer: B. Rods
Rods are more sensitive to low light levels. They help in night or dim-light vision but do not detect color well. Cones are mainly for color and bright-light vision.
A concave lens is commonly used to correct which defect of vision?
Correct Answer: A. Myopia
Myopia makes distant objects focus in front of the retina. A concave lens diverges light rays to shift the focus back onto the retina. This helps distant objects appear clear.
In the human eye, most of the refraction of light occurs at the?
Correct Answer: B. Cornea
The cornea provides the largest bending of light entering the eye. The air-to-cornea boundary has a big refractive index change. The eye lens mainly fine-tunes focus by accommodation.
Aqueous humor is primarily found in the space between the?
Correct Answer: C. Cornea and lens
Aqueous humor fills the front chambers of the eye. It lies mainly between the cornea and the lens. It also helps maintain proper intraocular pressure.
In bright light, the pupil becomes smaller mainly due to the action of the?
Correct Answer: C. Circular muscles of the iris
The iris controls pupil size with its muscles. In bright light, circular muscles contract to constrict the pupil. This reduces the amount of light entering the eye.
The least distance of distinct vision for a normal adult human eye is about?
Correct Answer: A. 25 cm
The near point of a normal adult eye is about 25 cm. At this distance, the eye can focus comfortably with maximum accommodation. This standard value is used in basic optics.
The blind spot in the human eye occurs because the retina at that point has?
Correct Answer: C. No photoreceptors
The correct answer is 'No photoreceptors'. The blind spot is where the optic nerve leaves the eye. That region lacks rods and cones, so it cannot detect light. The brain usually fills in the missing detail using both eyes.
The part of the retina responsible for the sharpest vision is the?
Correct Answer: A. Fovea (yellow spot)
The fovea has a very high density of cones. This allows the best visual acuity and fine detail perception. It is often called the yellow spot in basic texts.