Rewrite in a correct logical sequence :
Pupil, yellow spot, cornea, lens, aqueous humour (Path of entry of light into the eye from an object).

Rewrite in a correct logical sequence : Pupil, eye lens, vitreous humour, fovea, optic nerve.

Rewrite in a correct logical sequence : Oval window. Tympanum, Cochlea, Auditory canal, Ear ossicles (path through which a vibration of sound is transferred in the human ear).

Draw a diagram of the vertical section of human eye and label the following parts : (i) cornea, (ii) iris, (iii) aqueous humour, (iv) retina, (v) ciliary body, (vi) fovea centralis, (vii) choroid, (viii) pupil, and (ix) lens.

(a) A student suffering from myopia is not able to see distinctly the objects placed beyond 5 m . Two possible reasons due to which this defect of vision may have arisen. With the help of ray diagrams, explain : (i) Why the student is unable to see distinctly the objects placed beyond 5 m from his eyes. (ii) The type of corrective lens used to restore proper vision and how this defect is corrected by the use of this lens. (b) If in this case, numerical value of focal length of corrective lens is 5 m , find the power of the lens as per the new cartesion sign convention.

The steps involved in the mechanism of vision are given below. Arrange them in proper sequence and select the correct option. A. Dissociation of retinal from opsin and generation of potential difference in photoreceptor cells. B. Focusing of the light rays in visible wavelength on the corner through the lens. C. Generation of the action potential in ganglion cells through bipolar cells. D. Analysis of neural impulse and formation of aa image on the retina. E. Transmission of the action potential by the optic nerve to the visual cortex.

A : When viewing through a compound microscope, our eyes should be positioned not on the eye piece but a short distance away from it for best viewing. R : The image of the objective in the eye-piece is known as 'eye-ring' and if we position our eyes on the 'eye-ring' and the area of the pupil of out eye is greater or equal to the area of the eye ring, our eyes will collect all the light refracted by the objective.

(a) Write the function of each of the following parts of human eye : cornea, iris, crystalline lens, ciliary muscles (b) Millions of people of the developing countries of the world are suffering from corneal blindness. These persons can be cured by replacing the defective cornea with the cornea of a donated eye. A charitable socity of your city has organised a compaign in your neighbourhood in order to create awareness about this fact. If you are asked to participate in this mission how would you contribute in this noble cause ? (i) State the objective of organising such compaigns. (ii) List two arguments which you would give to motivate the people to donate their eyes after death. (iii) List two values which are developed in the persons who actively participate and contribute in such programmes.

A person is unable to see objects distinctly placed within 50 cm from his eyes. (a) Name the defect of vision the person is suffering from and list its two possible causes. (b) Draw ray diagram to show the defect in the above case. (c) Mention the type of lens used by him for the correction of the defect and calculate its power. Assume that the near point for the normal eye is 25 cm. (d) Draw a labelled diagram for the correction of the defect in the above case.

Given these structures 1. Lens 2. Aqueous humor 3. vitreous humor 4. Cornea Choose the correct sequence of the pathway of light from outside to inside the eyeball