Tag: eyes and their function

Questions Related to eyes and their function

The black pigment in the eye, which reduces the internal reflection is located in

  1. Retina

  2. Iris

  3. Choroid

  4. Cornea


Correct Option: C
Explanation:

The choroid is the part of the vascular coat in eyes. It also contains blood vessels that provide nourishment to the eye. It is pigmented towards a rear of the eye and absorbs light. It is a dark brown in colour. It darkens the cavity of the eyeballs to prevent internal reflection of light that might blur the image.

Thus, the correct answer is C.  

Skin is thinnest over.

  1. Back of hand

  2. Forehead

  3. Eye lids

  4. Sole of feet


Correct Option: C

Caring, diagnosis and cure of eye diseases

  1. Orthopaedics

  2. Ophthalmology

  3. Pathology

  4. Andrology


Correct Option: B
Explanation:
  • The word ''Opthalmology'' comes from the Greek roots ''Ophthalmol'' means ''Eye'' and ''Logos'' means ''Study''. Hence Ophthalmology literally means the ''The science of eyes''. 
  • An Ophthalmologist is a specialist in medical and surgical eye problems.
  • Hence Ophthalmology is the study of Caring, diagnosis and cure of eye diseases.
  • So, the correct answer is 'Ophthalmology'.

Skin melanocytes.

  1. Occur in stratum corneum

  2. Develop in dermis

  3. Pass into epidermis

  4. Both B and C


Correct Option: A

In a similarity with photographic camera, retina acts as

  1. Shutter

  2. Lens

  3. Diaphragm

  4. Film


Correct Option: D
Explanation:
In a photographic camera, image is formed on the film. Similarly, in eye, image is formed on the retina which is the light sensitive surface in the eye. The light rays enter the eye through an aperture called pupil. The eye lens which is biconvex, focus the light rays on the retina and an image is formed. Both the camera and eye have the ability to regulate the amount of light for image formation.
So, the correct answer is 'Film'.

A student has problem in reading as he is unable to contract his ______.

  1. Suspensory ligament

  2. Ciliary muscles

  3. Pupil

  4. Iris


Correct Option: B
Explanation:
A. Suspensory ligaments attach the eye lens with the ciliary body.
B. Ciliary muscles change the shape of eye lens to focus on nearby and distant objects.
C. Pupil is an aperture in eye through which light enters the eye.
D. Iris is pigmented and opaque structure of eye which controls the amount of light entering the eye by changing the size of pupil.
If a student has problem in reading, this means his eye lens is not able to focus on the alphabets and this is due to inability of the ciliary muscles to contract.
So, the correct answer is 'Ciliary muscles'.

Which is not a refractive medium of eye?

  1. Lens

  2. Vitreous humour

  3. Aqueous humour

  4. Pupil


Correct Option: D
Explanation:
A. Lens of eye is a crystalline structure in the eye ball which is held in place by ligaments that are attached to ciliary body. It is biconvex in nature and focus the light rays on the retina.
B. Aqueous humour is a transparent fluid present between cornea and lens.
C. Vitreous humour is a transparent gel present between lens and retina.
D. Pupil is the aperture of eye through rays enter the eye.
Refraction of light occurs when it enters a different medium and its speed gets changed. Pupil is not a refractive medium because it is an aperture or hole through which light is directly passing.
So, the correct answer is 'Pupil'.

Which part of lens in human eye is helpful in adjustment of focal length?

  1. Cornea

  2. Mucus

  3. Ciliary body

  4. Conjunctiva


Correct Option: C
Explanation:

The ciliary body is the structure in the eye that releases a transparent liquid (called the aqueous humour) within the eye. The ciliary body also contains the ciliary muscle, which changes the shape of the lens when your eyes focus on something. This process is called accommodation.

Which of the following statements is incorrect regarding lysozyme present in saliva ?

  1. It acts as an antibacterial agent.

  2. It prevents infections.

  3. It acts as an enzyme.

  4. All of these


Correct Option: A

Photosensitive compound in human eye is made up of

  1. Opsin and Retinal

  2. Opsin and Retinol

  3. Transducin and Retinene

  4. Guanosine and Retinol.


Correct Option: A
Explanation:

The photosensitive compound present in vision is called rhodopsin, also known as visual purple which consists of a large protein called opsin and retinal. Opsins are a group of light-sensitive proteins found in photoreceptor cells of the retina. Five classical groups of opsins are involved in vision, mediating the conversion of a photon of light into an electrochemical signal, the first step in the visual transduction cascade. Retinal allows certain microorganisms to convert light into metabolic energy. So, the correct answer is option A.