Eye MCQ Quiz - Objective Question with Answer for Eye - Download Free PDF

The correct answer is Concave.

Key Points

• A concave lens is used to correct myopia (nearsightedness).
• Myopia is a condition where distant objects appear blurry because the eye focuses the image in front of the retina.
• Concave lenses are diverging lenses, meaning they spread out light rays that have been refracted through them.
• These lenses help in shifting the focus of the light rays onto the retina, thus enabling clear distant vision.

Additional Information

• Myopia (Nearsightedness)
  • Myopia is a refractive error of the eye where close objects are seen clearly, but distant objects appear blurred.
  • This condition occurs when the eyeball is too long relative to the focusing power of the cornea and lens of the eye, causing light rays to focus at a point in front of the retina.
  • Genetics and environmental factors, such as prolonged near work, can contribute to the development of myopia.
  • It is commonly diagnosed through a standard eye examination and can be corrected with glasses, contact lenses, or refractive surgery.
• Concave Lenses
  • Concave lenses are thinner at the center and thicker at the edges.
  • They are used to correct myopia by diverging light rays before they enter the eye, thereby allowing the image to be focused on the retina rather than in front of it.
  • The lens power is measured in diopters (D), and the prescription for myopia will have a minus (-) sign indicating the concave lens.
  • In addition to glasses, concave lenses are also used in certain types of contact lenses designed for myopia correction.
• Convex Lenses
  • Convex lenses are thicker at the center and thinner at the edges, opposite to concave lenses.
  • They are used to correct hyperopia (farsightedness) and presbyopia by converging light rays to focus them on the retina.
  • Convex lenses are not suitable for myopia correction as they would worsen the condition.
• Bifocal Lenses
  • Bifocal lenses contain two different optical powers to correct both near and distant vision problems, typically for presbyopia.
  • They are not specifically used for myopia correction unless the patient also has presbyopia or hyperopia.
• Infrared (IR) Lenses
  • Infrared lenses are designed to filter and focus infrared light.
  • They are used in applications like thermal imaging cameras and night vision devices, not for correcting vision problems like myopia.

The correct answer is Beyond 25 cm.

Key Points

• Far-sightedness (Hyperopia) is a condition where distant objects can be seen more clearly than near objects.
• For a comfortable reading experience, a far-sighted person needs to hold the reading material beyond the near point of their vision.
• The typical near point for a normal eye is about 25 cm. In far-sighted individuals, this point is farther away.
• Therefore, to read comfortably, a far-sighted person needs to place the reading material beyond 25 cm from their eyes.

Important Points

• Far-sightedness is often corrected with convex lenses, which help focus the light directly onto the retina.
• The condition is common and can be present at birth or develop with age.
• Routine eye examinations can help detect far-sightedness and other vision issues early on.
• Proper lighting and holding the reading material at the correct distance can reduce eye strain for far-sighted individuals.

The correct  answer is Convex lens

Concept:

A convex lens is a lens that bulges outward in the middle and is thinner at the edges. It is thicker in the center than at the edges. Convex lenses are thicker in the middle than at the edges and can converge parallel rays of light passing through them to a focal point, forming a real image. They are commonly used in various optical devices and systems for magnification, focusing, and image formation.

Explanation:

In the human eye, there are two main lenses:

• Cornea: The cornea is the transparent, dome-shaped structure covering the front of the eye. It acts as the outermost lens of the eye and is primarily responsible for focusing incoming light rays onto the retina. The cornea contributes significantly to the eye's ability to refract light and plays a crucial role in determining the eye's overall focusing power.
• Crystalline Lens: The crystalline lens, often referred to simply as "the lens," is a flexible, transparent, biconvex structure located behind the iris and pupil. It is suspended in place by the suspensory ligaments attached to the ciliary body. The crystalline lens fine-tunes the focusing of light onto the retina by changing its shape through a process called accommodation. This allows the eye to focus on objects at different distances, enabling clear vision at varying distances.
• Both the cornea and the crystalline lens work together to refract light and focus it onto the retina, where images are formed and transmitted to the brain for visual processing. Together, these lenses play a crucial role in the eye's ability to perceive the surrounding environment and maintain clear vision.

Thus it implies that Convex lens is present in the human eye.

The correct answer is 25 cm. Key Points

• 25 cm is the average minimum distance of distinct vision for a young adult person with no defect in eyes.
• The minimum distance of distinct vision is the closest distance at which a person can see an object clearly.
• The distance varies for each individual and can change with age or eye defects.

Additional Information

• The nearest object that a person with "normal" vision (20/20 vision) can comfortably stare at is known as the least distance of distinct vision (LDDV) or reference seeing distance (RSD) in optometry.
• Stated differently, LDDV is the smallest reasonable distance that may be found between a visible item and the unaided eye.
• When viewed with the human eye, a lens's magnifying power (M) with a focal length (f in millimeters) can be computed as follows:
  • M = 250/f

The correct answer is The iris contracts the pupil to allow less light to enter the eye.Key Points

• When we move from a brightly lit room to a dimly lit room, our eyes take some time to adjust to the change in lighting.
• This is because the iris, which controls the amount of light entering the eye, needs to adjust to the new lighting conditions.
• This helps to improve the clarity of the image that is formed on the retina.
• Dilation of the eye lens actually allows more light to enter the eye, and so this would not help in a dimly lit room.​

Additional Information

• Iris:
  • The iris is a circular muscle in the eye that controls the size of the pupil and the amount of light entering the eye.
  • It is responsible for adjusting the amount of light that enters the eye based on the lighting conditions.
• Pupil:
  • ​The pupil is the black circular opening in the center of the iris that allows light to enter the eye.
  • Its size is controlled by the iris, which adjusts it based on the amount of light available.
• Vitreous humour:
  • The vitreous humour is a gel-like substance that fills the eye and helps to maintain its shape.
  • It does not have any control over the amount of light entering the eye.
• Cornea:
  • The cornea is a transparent layer at the front of the eye that helps to focus light onto the retina.
  • It does not have any control over the amount of light entering the eye.

The correct answer is The iris contracts the pupil to allow less light to enter the eye.Key Points

• When we move from a brightly lit room to a dimly lit room, our eyes take some time to adjust to the change in lighting.
• This is because the iris, which controls the amount of light entering the eye, needs to adjust to the new lighting conditions.
• This helps to improve the clarity of the image that is formed on the retina.
• Dilation of the eye lens actually allows more light to enter the eye, and so this would not help in a dimly lit room.​

Additional Information

• Iris:
  • The iris is a circular muscle in the eye that controls the size of the pupil and the amount of light entering the eye.
  • It is responsible for adjusting the amount of light that enters the eye based on the lighting conditions.
• Pupil:
  • ​The pupil is the black circular opening in the center of the iris that allows light to enter the eye.
  • Its size is controlled by the iris, which adjusts it based on the amount of light available.
• Vitreous humour:
  • The vitreous humour is a gel-like substance that fills the eye and helps to maintain its shape.
  • It does not have any control over the amount of light entering the eye.
• Cornea:
  • The cornea is a transparent layer at the front of the eye that helps to focus light onto the retina.
  • It does not have any control over the amount of light entering the eye.

The correct answer is 25 cm. Key Points

• 25 cm is the average minimum distance of distinct vision for a young adult person with no defect in eyes.
• The minimum distance of distinct vision is the closest distance at which a person can see an object clearly.
• The distance varies for each individual and can change with age or eye defects.

Additional Information

• The nearest object that a person with "normal" vision (20/20 vision) can comfortably stare at is known as the least distance of distinct vision (LDDV) or reference seeing distance (RSD) in optometry.
• Stated differently, LDDV is the smallest reasonable distance that may be found between a visible item and the unaided eye.
• When viewed with the human eye, a lens's magnifying power (M) with a focal length (f in millimeters) can be computed as follows:
  • M = 250/f

The correct answer is Light.

Key Points

• The dark circle in the iris's middle is the pupil of the eye.
• The colorful part of the eye, or iris, has a structure and hue that are particular to each individual.
• A portal that admits and controls the flow of light to the retina is the pupil of the eye.
• This step in the process contributes to how one see images.
• To regulate the amount of light allowed to enter the eye, the pupil opens and closes.
• Light enters the eye from the outside and travels through the pupil before passing through the transparent lens.
• This light is then focused on the retina, which is the layer of light sensitive cells at the back of the eye.
• Pupils expand or dilate to let in more light when it is dark.
• By doing this, vision is enhanced.
• pupil contracts to a very small diameter in strong light to shield our retina's delicate photoreceptors.
• In response to outside light, the pupil adjusts in size. 

​

The correct answer is The iris contracts the pupil to allow less light to enter the eye.Key Points

• When we move from a brightly lit room to a dimly lit room, our eyes take some time to adjust to the change in lighting.
• This is because the iris, which controls the amount of light entering the eye, needs to adjust to the new lighting conditions.
• This helps to improve the clarity of the image that is formed on the retina.
• Dilation of the eye lens actually allows more light to enter the eye, and so this would not help in a dimly lit room.​

Additional Information

• Iris:
  • The iris is a circular muscle in the eye that controls the size of the pupil and the amount of light entering the eye.
  • It is responsible for adjusting the amount of light that enters the eye based on the lighting conditions.
• Pupil:
  • ​The pupil is the black circular opening in the center of the iris that allows light to enter the eye.
  • Its size is controlled by the iris, which adjusts it based on the amount of light available.
• Vitreous humour:
  • The vitreous humour is a gel-like substance that fills the eye and helps to maintain its shape.
  • It does not have any control over the amount of light entering the eye.
• Cornea:
  • The cornea is a transparent layer at the front of the eye that helps to focus light onto the retina.
  • It does not have any control over the amount of light entering the eye.

The correct  answer is Convex lens

Concept:

A convex lens is a lens that bulges outward in the middle and is thinner at the edges. It is thicker in the center than at the edges. Convex lenses are thicker in the middle than at the edges and can converge parallel rays of light passing through them to a focal point, forming a real image. They are commonly used in various optical devices and systems for magnification, focusing, and image formation.

Explanation:

In the human eye, there are two main lenses:

• Cornea: The cornea is the transparent, dome-shaped structure covering the front of the eye. It acts as the outermost lens of the eye and is primarily responsible for focusing incoming light rays onto the retina. The cornea contributes significantly to the eye's ability to refract light and plays a crucial role in determining the eye's overall focusing power.
• Crystalline Lens: The crystalline lens, often referred to simply as "the lens," is a flexible, transparent, biconvex structure located behind the iris and pupil. It is suspended in place by the suspensory ligaments attached to the ciliary body. The crystalline lens fine-tunes the focusing of light onto the retina by changing its shape through a process called accommodation. This allows the eye to focus on objects at different distances, enabling clear vision at varying distances.
• Both the cornea and the crystalline lens work together to refract light and focus it onto the retina, where images are formed and transmitted to the brain for visual processing. Together, these lenses play a crucial role in the eye's ability to perceive the surrounding environment and maintain clear vision.

Thus it implies that Convex lens is present in the human eye.

The correct answer is 25 cm. Key Points

• 25 cm is the average minimum distance of distinct vision for a young adult person with no defect in eyes.
• The minimum distance of distinct vision is the closest distance at which a person can see an object clearly.
• The distance varies for each individual and can change with age or eye defects.

Additional Information

• The nearest object that a person with "normal" vision (20/20 vision) can comfortably stare at is known as the least distance of distinct vision (LDDV) or reference seeing distance (RSD) in optometry.
• Stated differently, LDDV is the smallest reasonable distance that may be found between a visible item and the unaided eye.
• When viewed with the human eye, a lens's magnifying power (M) with a focal length (f in millimeters) can be computed as follows:
  • M = 250/f

The correct answer is The iris contracts the pupil to allow less light to enter the eye.Key Points

• When we move from a brightly lit room to a dimly lit room, our eyes take some time to adjust to the change in lighting.
• This is because the iris, which controls the amount of light entering the eye, needs to adjust to the new lighting conditions.
• This helps to improve the clarity of the image that is formed on the retina.
• Dilation of the eye lens actually allows more light to enter the eye, and so this would not help in a dimly lit room.​

Additional Information

• Iris:
  • The iris is a circular muscle in the eye that controls the size of the pupil and the amount of light entering the eye.
  • It is responsible for adjusting the amount of light that enters the eye based on the lighting conditions.
• Pupil:
  • ​The pupil is the black circular opening in the center of the iris that allows light to enter the eye.
  • Its size is controlled by the iris, which adjusts it based on the amount of light available.
• Vitreous humour:
  • The vitreous humour is a gel-like substance that fills the eye and helps to maintain its shape.
  • It does not have any control over the amount of light entering the eye.
• Cornea:
  • The cornea is a transparent layer at the front of the eye that helps to focus light onto the retina.
  • It does not have any control over the amount of light entering the eye.

The correct answer is Concave.

Key Points

• A concave lens is used to correct myopia (nearsightedness).
• Myopia is a condition where distant objects appear blurry because the eye focuses the image in front of the retina.
• Concave lenses are diverging lenses, meaning they spread out light rays that have been refracted through them.
• These lenses help in shifting the focus of the light rays onto the retina, thus enabling clear distant vision.

Additional Information

• Myopia (Nearsightedness)
  • Myopia is a refractive error of the eye where close objects are seen clearly, but distant objects appear blurred.
  • This condition occurs when the eyeball is too long relative to the focusing power of the cornea and lens of the eye, causing light rays to focus at a point in front of the retina.
  • Genetics and environmental factors, such as prolonged near work, can contribute to the development of myopia.
  • It is commonly diagnosed through a standard eye examination and can be corrected with glasses, contact lenses, or refractive surgery.
• Concave Lenses
  • Concave lenses are thinner at the center and thicker at the edges.
  • They are used to correct myopia by diverging light rays before they enter the eye, thereby allowing the image to be focused on the retina rather than in front of it.
  • The lens power is measured in diopters (D), and the prescription for myopia will have a minus (-) sign indicating the concave lens.
  • In addition to glasses, concave lenses are also used in certain types of contact lenses designed for myopia correction.
• Convex Lenses
  • Convex lenses are thicker at the center and thinner at the edges, opposite to concave lenses.
  • They are used to correct hyperopia (farsightedness) and presbyopia by converging light rays to focus them on the retina.
  • Convex lenses are not suitable for myopia correction as they would worsen the condition.
• Bifocal Lenses
  • Bifocal lenses contain two different optical powers to correct both near and distant vision problems, typically for presbyopia.
  • They are not specifically used for myopia correction unless the patient also has presbyopia or hyperopia.
• Infrared (IR) Lenses
  • Infrared lenses are designed to filter and focus infrared light.
  • They are used in applications like thermal imaging cameras and night vision devices, not for correcting vision problems like myopia.

The correct answer is Beyond 25 cm.

Key Points

• Far-sightedness (Hyperopia) is a condition where distant objects can be seen more clearly than near objects.
• For a comfortable reading experience, a far-sighted person needs to hold the reading material beyond the near point of their vision.
• The typical near point for a normal eye is about 25 cm. In far-sighted individuals, this point is farther away.
• Therefore, to read comfortably, a far-sighted person needs to place the reading material beyond 25 cm from their eyes.

Important Points

• Far-sightedness is often corrected with convex lenses, which help focus the light directly onto the retina.
• The condition is common and can be present at birth or develop with age.
• Routine eye examinations can help detect far-sightedness and other vision issues early on.
• Proper lighting and holding the reading material at the correct distance can reduce eye strain for far-sighted individuals.

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