Optics part (3)

The normal eye can focus a sharp image of an object on the eye if the object located anywhere from the infinity to a certain point called near point the minimum distance of an object from the eye to have its clear image is called least distance vision it is about 25 cm for the normal eye and donated by D.

Dioptre is the unit of measurement for the refractive power of a lens the power of a lens is defined
as the reciprocal of its focal length in metres.
D=1/F
Where D is power of lens in dioptre and f is the focal length in metre converging lens has a positive optical power and diverging lens has negative optical power.

Dioptre is the unit of measurement for the refractive power of a lens the power of a lens is defined
as the reciprocal of its focal length in metres.
D=1/F
Where D is power of lens in dioptre and f is the focal length in metre converging lens has a positive optical power and diverging lens has negative optical power.

we know that
D=1/F
1 metre =100 cm
or f=100/D cm
f=100/2=50 cm

The power of the sunglass is 0 dioptre.

The exposure value EV is
EV∝N²*t

where N is the relative aperture and t is the exposure time hence among the given option  (a) has the maximum exposure value

The back of your eye is lined with a layer known as the retina. The retina operates in a similar way to the film inside a traditional (non-digital) camera. The middle part of the retina (known as the macula) takes care of your sharp vision. Your retina's nerve cells change light rays into electrical impulses and then sends them to the brain through the optic nerve.

The functioning of the human eye is similar to that of the photographic camera. The light rays travel into the cornea are refracted by the cornea and lens. In a normal eye, the image formed are transmitted from the retina to the brain along the optic nerve, where data processing takes place (the image is perceived the right way up).

The functioning of the human eye is similar to that of the photographic camera. The light rays travel into the cornea are refracted by the cornea and lens. In a normal eye, the image formed are transmitted from the retina to the brain along the optic nerve, where data processing takes place (the image is perceived the right way up).

In long-sightedness (Hypermetropia) the image of a nearby object is formed behind the retina. It results in close objects appearing blurry. The condition occurs in case the eyeball is too short or the focal length of the eye lens has been increased.The long sightedness is corrected by the convex lens.