Optics

visible electromagnetic waves

380nm Violet _ 760 nm red

Reflection

the bouncing back of a ray of light, sound, or heat when the ray hits a surface

Smooth thing surfaces have____reflaction

Clear reflection (specular)

Rough, dull surfaces have a ________ reflection.

diffuse reflaction(irregular)

Refraction of light

The bending of light as it passes from one medium to another

index of refraction

n=c/v

Snell's Law

n1sinθ1 = n2sinθ2

N1 in snells law

Index of refraction of first medium

ø1 in snells law

Angle of incidence

N2 in snells law

Index of rafractionof the second medium

ø2 in snell's law

Angle of refraction

lenses

transparent pieces of glass or plastic used for refracting light

A lens can______ light so that an image is formed

Focus

Types of lenses

convex (converging) and concave (diverging)

Convex lenses are

converging

Concave lenses are

diverging

Convex lenses are thicker in the

middle

Convex lenses focus light rays to

A focal point infront of the lens

focal length

the distance from the center of a lens to the focal point

main optical axis

The line passing through the focus and the center of the length

F F'

Focal point

f f'

Focal distance

s

Object distance

s'

Image distance

Ray passing through the center of the lens

Does not refract

Ray passing through the focus of the lens

Refracts parallel to the optical axis

A ray parallel to the optical axis will

Refract to the other focus

A diverging leans always produce a

Virtual image

lens formula

1/f = 1/s +1/s'

The distance s s' are +ve for

Real object and image

The distance f is +ve for

Convex lens

The distance s s' are -ve for

Virtual inmate and object

The distance f is -ve for

Concave lens

The hights h and h' are +ve when the images and objects are

Above the main optical axis

The hights h and h' are -ve when the images and objects are

Below the main optical axis

magnification law

The time as magnification m is the ratio of the image height to object height (m = h'/h=-s'/s)

If the image is erected m will be

+ve

If the image is inverted m will be

-Ve

power of lens equation

P = 1/f

When f is measured in m p is measured in

m^-1

The most powerful lens

Bend to the light to a greater degree then the weakest lens

Fovea

Center of Vision 0,25 mm

Correa

Bends light

Iris

Controls the amount of light

pupil

opening in the center of the iris

crystalline lens

Focuses light onto retina

Retina

Back of the eye

optic nerve (single wire)

Correspond as to blind spot

Choroid

Absorbs stray light

The mechanism of image forming

① light enters to eye through cornea which refracts it ② the light reaches the interior of the eye though the pupil ③ the light refract more though the crystalline lens onto the retina

Cornea has a small radius of

0,8cm

Most of the bending light occurs

Inside it

retina consists of________ which convert light into______then they're send to the brain via_____

Photosensitive cell, electrical signal, the optic nerve

The space between the Correa and the lens contains a

Waters fluid called aqueous humor

Behind the lens is a

Thin jelly fluid called vitreous humor

Both humors have An index of refraction equal to

1,336

crystalline lens has index of refraction equal to

1,437

Emmetropia (normal vision)

Eye is relaxes and focused on an object more than 6 meters away

Light rays in emmetropia is

Parallel,Reys are focused on the ritena without effort

If the gaze shifts to something closer

Light rays from the source are too divergent to be focused without effort

The eye is ______ focused things unless a _______ is made

automatically, conscious effort

near distance for adult

25cm

Near distance for infants

5-8cm

Near distance

The distance from the eye to the near point (xn)

far point

Point far from the eye at which (xf)

eye accommodation

Eye adjustment to see objects far away and close up

A in A = pf- pn is

Difference between the power

eye accommodation equation

A = pn-pf

power of accommodation

P= 1/f = 1/S + 1/s'

Short-sightedness (myopia)

the ability to see close objects clearly; distant objects appear blurry

myopia needs what type of lens?

Concave

Myopia (nearsightedness)

Light bent too strong

In my opt the image is formed

In-front of the retina

Longsightedness (hyperopia)

Distance object are in focus while nearby objects are blurry

Hypermetropia (farsightedness) need what lenses

Convex

A hypemeropic does what to light?

Can't bend light enough

In hypermeptropic images are formed

Behind retina

hypermetropic eye is

Further away then the typical 25 cm

Senile vision presbyopia

Accommodative power of the eye (their ability to focus) diminish with age

Senile vision (probyopia) can be corrected with

Reading glasses

In cylinder deviation astigmatism________because

The cornea dees not refract the light the same way in all directions, the cornea does not have a perfectly spherical shape

Astigmatism occurs with

Short or long sighteness

Cylinder deviation can be corrected with

Cylinder lenses

When light incident is 0>0c

The angle is totally reflected

total internal reflection

Sin 0c n2/n1

visible electromagnetic waves

380nm Violet _ 760 nm red

Reflection

the bouncing back of a ray of light, sound, or heat when the ray hits a surface

Smooth thing surfaces have____reflaction

Clear reflection (specular)

Rough, dull surfaces have a ________ reflection.

diffuse reflaction(irregular)

Refraction of light

The bending of light as it passes from one medium to another

index of refraction

n=c/v

Snell's Law

n1sinθ1 = n2sinθ2

N1 in snells law

Index of refraction of first medium

ø1 in snells law

Angle of incidence

N2 in snells law

Index of rafractionof the second medium

ø2 in snell's law

Angle of refraction

lenses

transparent pieces of glass or plastic used for refracting light

A lens can______ light so that an image is formed

Focus

Types of lenses

convex (converging) and concave (diverging)

Convex lenses are

converging