This document discusses optics and the human eye. It begins by explaining the nature of light as electromagnetic waves that can behave as both particles and waves. It then covers properties of light such as its speed and propagation in straight lines. The document discusses how the eye is sensitive to wavelengths between 600-350nm and absorbs shorter wavelengths. It explains light rays and beams and the dual wave-particle nature of light. Key optics concepts like reflection and refraction are summarized according to their laws. The document concludes by mentioning optics of the human eye.

1. Opthalmic and geometric
optics
Prasentation by saroj sah
rama university
kanpur up

2. Light
 Light is a forms of energy whose interaction with
retina and gives the sensation of sight.
 Nature of light:-
 Light is an electromagnetic waves.
 Light also have Dual nature i,e sometime acts as
wave and sometimes particles.
 The energy of photon diretly proportional to the
frequency of the electromagnetic wave.
 Ie E=hf h is planck’s constant

3. Properties of light
 Light is transverse in nature
 Light travels in straight line
 It can be detected by human eye
 Light travels at a speed of 3*10 m/s at empty
space
 It is forms of wave motion
 It is not deflected by electric and magnetic
field

4. Visible light and the eye
 Media of eye are uniformly permeable to the
visible rays between 600nm and 390nm.
 Cornea absorbs rays shorter than 295nm.
 Therefore, rays between 600nm and 295nm
only can reach the lens
 And lens absorbs rays shorter than 350
nm.therefore, rays between 600nm and
350nm can reach the retina in aphakic eye.
 So, Eye is most sensitive to yellow-green light

6. Light rays
 The path along which light energy travels is
called a rays.
 Line represents the path along which light
travels
 Arrow show the direction in which light
travels
 A bundles of light rays is a beam of light

7. Light beams
 3 differents types of light beams

8. Two nature of light
 1) wave nature of light
 2) Particles nature of light
 3) Dual nature of light
 Details of nature of light are as
 1) Wave nature of light :-
 Wavelength :-Wavelengh of light is defined
as the distance between two symmetrical
parts of the wave motion

9.  Amplitude:- Amplitude is the maximum
displacement of an oscillating particles from its
equilibrium position
 It is equal to the height of a peak or the depth of
a trough.
 Wave :- one complete oscillation of light is
called a wave

10.  Speed :- speed is the distance traveled per unit of
time .
 It is scalar quantity
 Energy :- hf ie h is plank’s constant and f is
frequency.
 2) Particle nature :-
 The particle like nature of light is modeled with
photons
 A photon means photo+electron
 It is carrier of electromagnetic energy and
interacts with other particles
 A photon has no mass and no charge

12. Reflection of light
 Reflection of light is the phenomenon of change in
the path of light rays without any change in the
medium
 The light rays falling on a reflecting surface are
called incident rays
 And those reflected by surface is called reflected
rays
 A line drawn at right angle to the surface is called
normal

13. Laws of reflection
 1)The incident ray,reflected rays and normal are lies
on the same plane
 2)The angle of incident(i) is equal to angle of
reflection(r)

14. Refraction of light
 Refraction of light is the phenomenon of change
in the path of light, when it goes from one
medium to another
 # Laws of refraction :-
 The incident(i) and refracted (r) rays are one
opposite side of the normal (N) and all the three
are in the same plane
 snell’s law
 sina n1=sina
n2

15. Optic of human eye