This is a presentation of Study on human eye.

1. Name of Student Student ID
Md.Hasan Tanvir BTE-01005518
Pranayraj Barua Shubha BTE 01005539
Md.Shohrab Hosen BTE 00905486
Md.Kamal Hossain BTE 00905491
Study on Human eye
Course code:222
Course title: Color chemistry Lab

3. Contents
 Introduction.
 Component of eye.
 mechanism of Color vision.
 Defects of vision and their correction.
 Conclusion.

4. Introduction
 Eye is the lite sensative organ of vision in animals. The
actual process of seeing is performed by thr brain rather
then b y the eye.The function of the eye is to translate the
electromagnatic vibration of lite into patterns of nerve
impulses that are transmitted to the brain.

5.  Cornea: The front part of
the eye is covered by
transparent spherical
membrane called cornea.
Cornea

6.  Iris: Just behind the
cornea is a dark
coloured muscular
diaphragm which has
a small circular
opening in the middle
Iris

7.  Pupil: Pupil is the small
circular opening of iris.
The pupil appears black
because no light is
reflected from it.
pupil

8.  Eye Lens: The eye
lens is a convex lens
made of a transparent
jelly like
proteinaceous
material.
lens

9.  Ciliary muscles:
The eye lens is held
in position by ciliary
muscles. The ciliary
muscles help in
changing the
curvature and focal
length of the eye
lens.
Ciliary muscles

10.  Retina: The inner back
surface of the eye ball is
called retina. It is a semi-
transparent membrane
which is light sensitive
and is equivalent to the
screen of a camera.
Retina

11. Vitreous
human

12.  Blind Spot: It is a
spot at which the optic
nerve enters the eye
and is insensitive to
light and hence the
name.
Blind
spot

13. Trichromatic theory:-
The photocells in our retina ,called
coned are resdponsible for our color
vision.There are 3 types of cones,
each with a different iodopsin(a
photosentative pigtment)
Eaqch types of idopsin can absorb
and respond to a range of
wavelength:
Erythrolabe:max.absorptionat565n
m(red)
Chlorolabe:max.absorptionat535nm
(green)
Cyanolabe:max.absorptionat440nm
(blue)

14.  Different colors can be seen from the integration of
impulse from these types of cone pigment
 The resultant color depend on the differential stimulation
of each pigment.
 Opponent history:-Hering points out that some colors
appears to be “Mutually exclusive”. It seems that both
theories are useful in that :
 The color vision is trichromatic at the level of
photoreceptors.
 Colours opponency is explained by subsequent neural
processing.

15. Defects of Vision and Their Correction
Myopia or Near-sightedness.
Hypermetropia or Farsightedness.
Presbyopia.
Cataract.

16. Myopia or Near-sightedness
Myopia :The light from a
distant object arriving at the
eye lens may get converged
at a point in front of the
retina in the vitreous body.
Correction for myopia: To
compensate this, we
interpose a concave lens
between the eye and the
object, with the diverging
effect desired to get the
image focused on the
retina.

17. Hypermetropia : If the eye-
lens focuses the incoming light
at a point behind the retina,
this defect is called far
sightedness or hypermetropia.
Correction for hypermetropic
eye: A convergent lens(convex
lens) is needed to compensate
for the defect in vision.
Correction of Hypermetropia

18. Presbyopia is a common type of vision disorder that occurs as you age. It is
often referred to as the aging eye condition. Presbyopia results in the inability
to focus up close, a problem associated with refraction in the eye.
Presbyopia

19. Cataract: The crystalline lens of people at old age becomes milky and
cloudy. This condition is called cataract. This causes partial or complete
loss of vision. It is possible to restore vision through a cataract surgery.
Cataract

20. Conclusion
 The ability of the eye focus both near and distant object,by
adjusting its focus length, is called the accommodation of the
eye .
 Eyes are the chief organs of vision in human body and hence
termed as photoreceptors.
 Vision is one of the most important gifts which god has offered
us. It is said, “health is wealth”. But not wealth in the universe is
equivalent to the vision gift. The human eye is one of the most
important organs in the human body. It is very sensitive and
exposed to a variety of diseases that’s why we should take a lot
of care to protect it and keep safe. Recently, a lot of eye
diseases have been discovered and spread and people has
begun suffering from them. Scientists and researchers are doing
their best to find solution for these serious diseases..