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📘 Study MCQs
Q1. What is the name of the transparent front part of the eye that allows light to enter?
• Retina
• Sclera
• Cornea
• Iris
Answer: Cornea
The cornea is the transparent, dome-shaped front part of the eye that acts as a window and allows light to enter.
Q2. Which part of the eye controls the size of the pupil?
• Retina
• Iris
• Cornea
• Lens
Answer: Iris
The iris is the coloured part of the eye. It contains muscles that control the size of the pupil and regulate the amount of light entering.
Q3. Which part of the eye is responsible for forming the image?
• Cornea
• Pupil
• Retina
• Ciliary muscle
Answer: Retina
The retina is the light-sensitive layer at the back of the eye where images are formed.
Q4. What is the function of the lens in the human eye?
• To control light intensity
• To provide colour
• To focus light onto the retina
• To send signals to the brain
Answer: To focus light onto the retina
The lens, located behind the iris, fine-tunes the focus of light rays onto the retina.
Q5. The ability of the eye lens to adjust its focal length is called?
• Persistence of vision
• Power of accommodation
• Dispersion
• Refraction
Answer: Power of accommodation
The power of accommodation is the eye’s ability to change the focal length of its lens to see both near and distant objects clearly.
Q6. Which muscles help in changing the focal length of the eye lens?
• Iris muscles
• Optic muscles
• Ciliary muscles
• Rectus muscles
Answer: Ciliary muscles
The ciliary muscles contract or relax to change the curvature and thus the focal length of the eye lens.
Q7. For a normal eye, what is the least distance of distinct vision?
• 25 meters
• 25 centimeters
• 50 centimeters
• Infinity
Answer: 25 centimeters
The minimum distance at which an object can be seen clearly without strain is about 25 cm for a normal adult eye.
Q8. When looking at a distant object, what is the state of the ciliary muscles?
• They contract
• They relax
• They expand
• They become rigid
Answer: They relax
When viewing distant objects, ciliary muscles relax, making the lens thinner, which increases its focal length.
Q9. Why do we have two eyes instead of one for vision?
• For better colour vision
• To increase the field of view
• For depth perception and 3D vision
• All of the above
Answer: All of the above
Two eyes provide a wider field of view, help in judging distances (depth perception), and give a three-dimensional view of objects.
Q10. Which defect of vision is also known as nearsightedness?
• Hypermetropia
• Presbyopia
• Myopia
• Astigmatism
Answer: Myopia
Myopia, or nearsightedness, is a defect where a person can see nearby objects clearly but distant objects appear blurred.
Q11. In which defect does the image form in front of the retina?
• Hypermetropia
• Presbyopia
• Myopia
• Cataract
Answer: Myopia
In myopia, the eyeball is too long or the lens is too curved, causing light to focus in front of the retina.
Q12. What type of lens is used to correct myopia?
• Convex lens
• Concave lens
• Cylindrical lens
• Bifocal lens
Answer: Concave lens
A concave (diverging) lens is used to correct myopia as it diverges the light rays before they enter the eye, helping the image form on the retina.
Q13. Which defect of vision is also known as farsightedness?
• Myopia
• Hypermetropia
• Presbyopia
• Glaucoma
Answer: Hypermetropia
Hypermetropia, or farsightedness, is a defect where a person can see distant objects clearly but nearby objects appear blurred.
Q14. In which defect does the image form behind the retina?
• Myopia
• Hypermetropia
• Presbyopia
• Both Hypermetropia and Presbyopia
Answer: Hypermetropia
In hypermetropia, the eyeball is too short or the lens is too flat, causing light to focus behind the retina.
Q15. What type of lens is used to correct hypermetropia?
• Concave lens
• Convex lens
• Plano-concave lens
• Bifocal lens
Answer: Convex lens
A convex (converging) lens is used to correct hypermetropia as it converges the light rays before they enter the eye, helping the image form on the retina.
Q16. What is the common age-related defect where the eye loses its power of accommodation?
• Myopia
• Hypermetropia
• Presbyopia
• Cataract
Answer: Presbyopia
Presbyopia is an age-related defect where the ciliary muscles weaken and the lens becomes less flexible, reducing the eye’s power of accommodation.
Q17. How is presbyopia usually corrected?
• Using concave lenses
• Using convex lenses
• Using bifocal lenses
• Using cylindrical lenses
Answer: Using bifocal lenses
Bifocal lenses have both convex (upper part for distant vision) and concave (lower part for near vision) sections to correct presbyopia.
Q18. What is the splitting of white light into its constituent colours called?
• Reflection
• Refraction
• Dispersion
• Scattering
Answer: Dispersion
Dispersion is the phenomenon where white light splits into its seven constituent colours (VIBGYOR) when passing through a prism.
Q19. Through which geometrical shape does light pass to cause dispersion?
• Rectangular glass slab
• Spherical lens
• Glass prism
• Concave mirror
Answer: Glass prism
A glass prism, with a triangular cross-section, refracts light and causes dispersion due to different angles of refraction for different colours.
Q20. Which colour of light deviates the least when passing through a prism?
• Violet
• Indigo
• Red
• Blue
Answer: Red
Red light has the longest wavelength and deviates the least, while violet light (shortest wavelength) deviates the most.
Q21. Which colour of light deviates the most when passing through a prism?
• Red
• Green
• Yellow
• Violet
Answer: Violet
Violet light has the shortest wavelength and bends the most when refracted through a prism.
Q22. The band of seven colours obtained after dispersion is called?
• Light spectrum
• Rainbow
• Reflection band
• Spectrum
Answer: Spectrum
The band of coloured components of light (VIBGYOR) is called a spectrum.
Q23. What is the bending of light as it passes from one medium to another called?
• Reflection
• Dispersion
• Refraction
• Scattering
Answer: Refraction
Refraction is the bending of light rays when they pass from one transparent medium to another of different optical density.
Q24. What is the role of the optic nerve in the eye?
• To control pupil size
• To focus light
• To carry visual signals to the brain
• To provide nutrition to the eye
Answer: To carry visual signals to the brain
The optic nerve carries the electrical signals generated by the retina’s photoreceptor cells to the brain for interpretation.
Q25. The black opening in the centre of the iris is called?
• Cornea
• Retina
• Pupil
• Blind spot
Answer: Pupil
The pupil is the dark circular opening in the centre of the iris that allows light to enter the eye.
Q26. Which cells in the retina are sensitive to bright light and colour?
• Rods
• Cones
• Optic nerves
• Ciliary cells
Answer: Cones
Cone cells are photoreceptor cells in the retina that function best in bright light and are responsible for colour vision.
Q27. Which cells in the retina are sensitive to dim light?
• Rods
• Cones
• Ganglion cells
• Bipolar cells
Answer: Rods
Rod cells are photoreceptor cells in the retina that are highly sensitive to dim light and help in night vision.
Q28. The point on the retina where the optic nerve leaves the eye has no photoreceptor cells. What is it called?
• Macula
• Fovea
• Yellow spot
• Blind spot
Answer: Blind spot
The blind spot is the point on the retina where the optic nerve exits; it has no rods or cones, so images falling here are not seen.
Q29. Which part of the eye gives it its distinctive colour (e.g., blue, brown)?
• Cornea
• Retina
• Pupil
• Iris
Answer: Iris
The iris contains pigment that determines the eye’s colour and controls the amount of light entering through the pupil.
Q30. The process by which light rays converge or diverge by a lens is called?
• Reflection
• Refraction
• Dispersion
• Accommodation
Answer: Refraction
Lenses work by refracting (bending) light rays to converge or diverge them, thus forming images.
Q31. What happens to the pupil in bright light?
• It becomes larger
• It becomes smaller
• It disappears
• It changes colour
Answer: It becomes smaller
In bright light, the circular muscles of the iris contract, making the pupil smaller to reduce the amount of light entering.
Q32. What happens to the pupil in dim light?
• It becomes smaller
• It becomes larger
• It remains the same
• It closes
Answer: It becomes larger
In dim light, the radial muscles of the iris contract, making the pupil larger (dilated) to allow more light to enter.
Q33. In a myopic eye, where does the image of a distant object form?
• On the retina
• Behind the retina
• In front of the retina
• No image is formed
Answer: In front of the retina
Due to excessive curvature of the lens or elongation of the eyeball, the image of a distant object focuses in front of the retina.
Q34. A person with hypermetropia has difficulty seeing which objects?
• Distant objects
• Nearby objects
• Both nearby and distant objects
• Coloured objects
Answer: Nearby objects
In hypermetropia, the image of nearby objects is formed behind the retina, making them appear blurred.
Q35. What is the name of the transparent, jelly-like substance that fills the main cavity of the eye?
• Aqueous humour
• Vitreous humour
• Tears
• Mucus
Answer: Vitreous humour
The vitreous humour is a clear, gel-like substance that fills the space between the lens and the retina, maintaining the eye’s shape.
Q36. What is the liquid found between the cornea and the lens called?
• Vitreous humour
• Blood
• Aqueous humour
• Tears
Answer: Aqueous humour
The aqueous humour is a watery fluid between the cornea and the lens that provides nutrition and maintains eye pressure.
Q37. The phenomenon due to which we continue to see an image for a short time after the object is removed is called?
• Power of accommodation
• Dispersion
• Persistence of vision
• Refraction
Answer: Persistence of vision
Persistence of vision is the ability of the eye to retain an image for about 1/16th of a second after the object is gone, allowing motion perception.
Q38. The ability of the eye to see objects in three dimensions (3D) is called?
• Binocular vision
• Stereoscopic vision
• Monocular vision
• Peripheral vision
Answer: Stereoscopic vision
Having two eyes provides slightly different images that the brain combines to perceive depth and three-dimensional structure (stereoscopic vision).
Q39. Which defect can arise due to excessive curvature of the cornea?
• Hypermetropia
• Presbyopia
• Myopia
• Cataract
Answer: Myopia
Excessive curvature of the cornea (or lens) causes light to focus in front of the retina, leading to myopia.
Q40. What is the white part of the eye called?
• Cornea
• Sclera
• Iris
• Retina
Answer: Sclera
The sclera is the tough, white, outer layer of the eyeball that provides protection and structure.
Q41. The middle layer of the eye, rich in blood vessels, is called?
• Retina
• Choroid
• Sclera
• Cornea
Answer: Choroid
The choroid is the middle layer between the sclera and retina. It is dark and rich in blood vessels, providing nourishment to the eye.
Q42. Which phenomenon of light is responsible for the twinkling of stars?
• Reflection
• Refraction
• Dispersion
• Atmospheric refraction
Answer: Atmospheric refraction
The twinkling of stars is caused by atmospheric refraction, where starlight continuously bends as it passes through layers of air with varying densities.
Q43. The far point of a normal eye is at:
• 25 cm
• 100 cm
• Infinity
• At the lens
Answer: Infinity
A normal eye can see distant objects (at infinity) clearly when the ciliary muscles are fully relaxed.
Q44. What is the near point of a young adult with normal vision?
• 25 m
• 25 cm
• 2.5 cm
• Infinity
Answer: 25 cm
The near point, or least distance of distinct vision, is about 25 cm for a young adult with normal eyesight.
Q45. What type of image is formed on the retina of the human eye?
• Virtual and erect
• Real and inverted
• Real and erect
• Virtual and inverted
Answer: Real and inverted
The eye lens forms a real, inverted, and diminished image of the object on the retina. The brain later interprets it as erect.
Q46. Which part of the eye is most sensitive and has the maximum concentration of cone cells?
• Blind spot
• Optic nerve
• Fovea or yellow spot
• Choroid
Answer: Fovea or yellow spot
The fovea, a small pit in the macula of the retina, has the highest concentration of cone cells, providing the sharpest colour vision.
Q47. What is the main cause of presbyopia?
• Elongation of eyeball
• Shortening of eyeball
• Weakening of ciliary muscles and hardening of lens
• Excessive curvature of cornea
Answer: Weakening of ciliary muscles and hardening of lens
With age, the ciliary muscles weaken and the eye lens becomes less flexible and slightly rigid, reducing its ability to change shape (accommodate).
Q48. What is the unit of power of a lens?
• Meter (m)
• Centimeter (cm)
• Watt (W)
• Dioptre (D)
Answer: Dioptre (D)
The power of a lens is the reciprocal of its focal length (in meters). Its SI unit is dioptre (D).
Q49. What happens when white light passes through a glass prism?
• It gets absorbed
• It gets reflected
• It bends and splits into colours
• It passes straight
Answer: It bends and splits into colours
A prism refracts (bends) the light, and different colours bend by different amounts due to dispersion, forming a spectrum.
Q50. A rainbow is a natural example of which phenomenon?
• Reflection of light
• Dispersion of sunlight
• Scattering of light
• Total internal reflection
Answer: Dispersion of sunlight
A rainbow is formed when sunlight is dispersed by water droplets in the atmosphere, acting like tiny prisms.