Near point is the nearest point at which the object s can be seen distinctly.
The near point of an eye with healthy vision is 25 cm.
Far point is the farthest point at which the object s can be seen distinctly. The far point of an eye with healthy vision is at infinity.
The ability of the eye to form an image on the retina by adjusting the focal length of the lens , irrespective of the object, is the power of accommodation. For a person with long sightedness the
size of the eye ball is smaller or power of the eye lens is low
Long sightedness can be corrected by using convex lens of suitable focal length.
For a person with short sightedness size of the eye ball is larger or the power of the eye lens is high.
Short sightedness can be rectified by using concave lens of suitable focal length.
When sunlight is passed through a glass prism spectrum VIBGYOR is obtained.
Sunlight is composite light.
Red colour is seen at the upper edge of the rainbow.
Violet colour is seen at the lower edge of the rainbow.
When an object is viewed by a person, its image remains in the retina of the eye for a time interval of 1/16 second after seeing it. This phenomenon is called Persistence of vision.
Scattering is the change in direction brought out by the irregular and partial reflection of light when it hits the particles of the medium.
As the size of the particle increases, the rate of scattering also increases.
If the size of the particle is greater than the wavelength of light, then the scattering is same for all colours.
The near point of an eye with healthy vision is 25 cm.
Far point is the farthest point at which the object s can be seen distinctly. The far point of an eye with healthy vision is at infinity.
The ability of the eye to form an image on the retina by adjusting the focal length of the lens , irrespective of the object, is the power of accommodation. For a person with long sightedness the
size of the eye ball is smaller or power of the eye lens is low
Long sightedness can be corrected by using convex lens of suitable focal length.
For a person with short sightedness size of the eye ball is larger or the power of the eye lens is high.
Short sightedness can be rectified by using concave lens of suitable focal length.
When sunlight is passed through a glass prism spectrum VIBGYOR is obtained.
Sunlight is composite light.
Red colour is seen at the upper edge of the rainbow.
Violet colour is seen at the lower edge of the rainbow.
When an object is viewed by a person, its image remains in the retina of the eye for a time interval of 1/16 second after seeing it. This phenomenon is called Persistence of vision.
Scattering is the change in direction brought out by the irregular and partial reflection of light when it hits the particles of the medium.
As the size of the particle increases, the rate of scattering also increases.
If the size of the particle is greater than the wavelength of light, then the scattering is same for all colours.