anatomy organs of vision

Anatomy organs
of vision
TABLE OF CONTENTS
Introduction
Main
1. Summary of the eye
2. The structure of the eye
4. Diseases of the Eye
4.1 Myopia
4.2 Farsightedness
4.3 Color Blindness
5. The human eye (Table)
conclusion
Introduction
Ophthalmology - the science that studies the
anatomy, physiology of the body, diseases related
to the organs of vision, as well as the structure of
blindness.
Objectives of Ophthalmology - the maximum
reduction in the number of blind and visually
impaired. According to WHO, in the world there are
42 million blind and visually impaired. And every
year there is an increase of this index, and
represents an increase of 3-6% per year.
I chose the theme of "Anatomy of the
vision" because this issue is very
relevant today, as a large number of
people, especially school children now
suffer from various eye diseases caused
by visual overload, namely emission
computer, TV, reading and load a letter
to the school, and of course, not
adherence to the simple rules to
preserve the health of your eyes.
A summary of the eyes
The perception of visual stimuli:
Light enters the eyeball through the pupil. Lens and
vitreous body and serve for focusing the light rays onto
the retina. Oculomotor muscles - six of them - ensures
that the eyeball to the image of the object would fall
exactly on the retina, the macula at her. In the receptors
of the retina converts light into nerve impulses that are
sent along the optic nerve to the brain - the visual area of
the cerebral cortex. Begins in the retina analysis of color,
shape, light object, its parts end up in the visual cortex.
There is going to all the information, it is decrypted and
generalized. As a result, develops understanding of the
subject.
Anatomy organs of vision
A - auxiliary apparatus,
eye muscles
Б - diagram of the
structure of the visual
analyzer
В - the structure of the
retina
Г - Diagram of the eyeball
Д - eye color
discrimination receptors
The structure of eyedall
1 - cornea
2 - iris
3 - albuginea (sclera)
4 - choroid
5 - pigment layer
6 - yellow spot
7 - the optic nerve
8 - retina
9 - Muscle
10- ligament of the lens
11 - lens
12 - pupil
In the retina, located receptors: rods (receptors
twilight) and cones (they have a lower sensitivity, but
can respond to color).
Most of the cones
located on the retina
in front of the pupil,
in the macula.
Near this spot
is a place of exit
optic nerve,
there are no receptors
therefore it is called the blind spot.
The structure of the auxiliary
apparatus
The muscles that move the eyeball
Path of the rays in the
clinical eye refraction
- myopia
Figure 1. Focus the image
myopic eyes
Figure 2 Nearsightedness
(myopia)
Path of the rays in
the clinical eye
refraction - hyperopia
Figure 1. Focus the image
farsighted eye
Figure 2 arsightedness
(hyperopia)
What do you see?
The structure of eye
Eye - the organ of vision - can be compared with a window into
the world. Approximately 70% of all information we receive
through vision, such as the shape, dimensions, color of objects,
the distance to them and others. Visual Analyzer monitors the
motor and career rights; thanks to the vision we can learn from
books the experience of mankind.
The main purpose of the eye, or rather the visual analyzer - a
vision of objects of the environment and the possibility of
orientation in it - provides many support functions. Among them
accommodative forming clarity subjects perceived environment on
the retina, is one of the leading. Each of these functions, including
accommodative realized their anatomical structures, collectively
representing the structure of the eyeball.
The organ of vision consists of the eyeball and the
auxiliary unit. Auxiliary device - is eyebrows, eyelids
and eyelashes, lacremal iron, lacrimal ducts,
oculomotor muscles, nerves and blood vessels.
Eyebrows and eyelashes protect the eyes from dust. In
addition, eyebrows divert flowing sweat from his brow.
Everyone knows that a person is constantly blinking (2
- 5 centuries of movements in 1 min). But what do they
know? It turns out that the surface of the eye when
blinking wetted tear fluid, which protects it from drying
out, while at the same time free of dust. Slёznuyu
liquid produce lacrimal gland. It contains 99% water
and 1% salt. At night stands 1 g tear fluid, it's going in
the inner corner of the eye, and then gets into the tear
ducts that put her into the nasal cavity. If a person
cries, slёznaya fluid does not have time to leave the
tubules in the nasal cavity. Then the tears flow through
the lower eyelid and trickling down our face.
Глазное яблоко располагается в углублении черепа –
глазнице. Оно имеет шаровидную форму и состоит из
внутреннего ядра, покрытого тремя оболочками:
наружной – фиброзной, средней – сосудистой и
внутренней – сетчатой. Фиброзная оболочка подразделяется
на заднюю непрозрачную часть – белочную оболочку, или
склеру, и переднюю прозрачную роговицу. Роговица
представляет собой выпукло-вогнутую линзу, через которую
свет проникает внутрь глаза. Сосудистая оболочка
расположена под склерой. Её передняя часть называется
радужкой, в ней содержится пигмент, определяющий цвет
глаз. В центре радужной оболочки находится небольшое
отверстие – зрачок, который рефлекторно с помощью мышц
может расширяться или сужаться, пропуская в глаз
необходимое количество света. Собственно сосудистая
оболочка пронизана густой сетью кровеносных сосудов,
питающих глазное яблоко. Изнутри к сосудистой оболочке
прилежит слой пигментных клеток, поглощающих свет,
поэтому внутри глазного яблока свет не рассеивается.
Непосредственно за зрачком находится двояковыпуклый
прозрачный хрусталик. Он может рефлекторно менять свою
кривизну, обеспечивая четкое изображение на сетчатке –
внутренней оболочке глаза.
Nearsightedness (myopia)
Nearsightedness (myopia) - mostly due to hereditary
disease, when in a period of intense visual load, due to
the weakness of the ciliary muscle, circulatory disorders
of the eye occurs stretch dense covering of the eyeball
(the sclera) in the anteroposterior direction. Eyes
instead takes the form of spherical ellipsoid. Because of
this extension of the longitudinal axis of the eye images
of objects focuses not on the retina, but in front of it,
and the person tends to bring everything to the eyes,
use glasses with scattering ("minus") lenses to reduce
the refractive power of the lens. Myopia unpleasant fact
that the progression of the disease occur in dystrophic
lesions of the eye leading to irreversible loss of vision
not corrected by glasses vision loss. To avoid this, it is
necessary to combine the experience and knowledge of
an ophthalmologist with perseverance and the will of
the patient in the sustainable distribution of visual load,
periodic self-monitoring of the state of their visual
function.
Farsightedness (hyperopia)
Farsightedness (hyperopia) - is a congenital condition,
especially the structure of the eyeball: it is a short eye or
eyes with poor optics. Rays while going behind the
retina. To this eye could see in front of him to place the
collecting ("plus") lenses. This condition may be long
"hiding" and appear in 20-30 years and later in life; it all
depends on the eye of reserves and the degree of
farsightedness. Age farsightedness (presbyopia). With
age, the power of accommodation decreases gradually,
by reducing the elasticity of the lens and the ciliary
muscle. State occurs when the muscle is no longer able to
minimize and lens, losing elasticity, can not accept the
maximum spherical shape - as a result of the eye loses
the ability to distinguish small, closely spaced objects to
it, and the person tends to push them away from the eyes
(to facilitate the work of ciliary muscles). For the
correction of hyperopia are assigned points for proximity
to the collecting ("plus") lenses. The correct mode of
visual work and systematic training of view will
significantly push the timing of the farsightedness for
many years.
Color blindness
Color blindness - the inability to
correctly identify certain colors. ?
It may be hereditary nature or be
caused by disease of the optic
nerve or retina.
The test for color blindness
 Acquired color blindness occurs only on the eye,
which struck the retina or optic nerve. His is the
progressive deterioration over time and the difficulty
in distinguishing between blue and yellow.
 Hereditary blindness is more common, affects
both eyes and does not deteriorate with time. This
embodiment of color blindness in varying degrees of
severity is present in 8% of men and 0.4% of
women.
Hereditary blindness associated with the Xchromosome and almost always passed from mother
carrying the gene to her son.
The human eye
Systems
And appendages of
the eye
Structure
Functions
Auxiliary
Eyebrows
Hair growing from the
inner to the outer corner of
the eye
withdrawn sweat
Eyelids
Skin folds with eyelashes
Protect your eyes from the
light rays, dust
lacrimal apparatus
Lacrimal gland and the
tears which eliminates
liquidт
Tears moisten, cleanse,
disinfect eye
tunica
The dense outer shell
consists of connective
tissue
Protective
vascular
Average shell permeated
with blood vessels
Power eyes
retina
The inner shell consists of
photoreceptors: rods and
cones
perception of light
shell
Optical
Cornea
The transparent front part
of the tunica albuginea
Refracts light rays
Aqueous humor
Clear liquid, located
behind the cornea
Skips the rays of light
iris
The front part of the
choroid
Contains a pigment that
gives color eye
pupil
The hole in the iris muscle
surrounded
Regulates the amount of
light
crystalline lens
Lenticular, elastic,
clear lens, surrounded by
the ciliary muscle
refracts and
focus the rays
light has accommodation
vitreous
body
clear
gelatinous body
fills the eye
apple, misses
light rays
perceive light
photoreceptors
In the retina, in the form of
rods and cones (about 125
million. Rods and 6 million.
Cones,
the main mass
cones
concentrated in the central
area of the retina - in the
macula; as
distance from the center
number of cones decreases
and
rods increases. On the
periphery of the retina are
only
coli)
sticks
takes the form of (vision in
low light), cones - color
visual
nerve
The nerve cells of the
cortex,
from which
starting fiber optic,
connected to
processes of photoreceptor
neurons
Perceives excitation is
transmitted to the visual
area
cerebral cortex, where the
excitation and analysis
occurs forming visual
images
Conclusion
Eye - a complex physiological system
photooptically, the ability to perceive the
impact of the environment in the form of
radiant energy. I also found some simple
rules you need to follow to keep your
vision for years to come and how to eat,
as the food and the overall health of the
body plays an important role in
maintaining eye health. I learned how to time and as
soon as possible to recognize the various disorders of
the functioning of the body, how to protect their eyes
from overload and prevent the development of
diseases of the eye, independently regularly monitor
the status of their visual function. I learned more about
the structure and functioning of our body of diseases
such as nearsightedness, farsightedness, astigmatism,
cataracts, glaucoma and other, their prevention and
treatment. Because it is often the person who receives
enough information about this or other eye diseases,
disorders functioning of the visual organ can bring
everything to the extreme, that perhaps you can still
fix at best, and at worst, all of which can lead to
complete loss of vision - blindness .
Treat your eyes gently and
carefully !!!