Structure And Functions Of Eye Pdf

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Eyes are organs of the visual system. They provide animals with vision , the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and convert it into electro-chemical impulses in neurons.

Human Eye: Anatomy, parts and structure

Jump to content. The five senses include sight, sound, taste, hearing and touch. Sight, like the other senses is closely related to other parts of our anatomy. The eye is connected to the brain and dependent upon the brain to interpret what we see. How we see depends upon the transfer of light.

Special cells called cones and rods are located in the retina. These cells are known as photoreceptors and help absorb light. The majority of the cones are located in the macula, or central area, of the retina. Cone cells help us see colour and detail. Similarly, the macula allows us to read and clearly recognize people's facial details, such as eye colour and whether they have freckles.

Anatomy of the Eye

Parts of the Eye. Here I will briefly describe various parts of the eye:. The sclera is the white of the eye. The Cornea. The cornea is the clear bulging surface in front of the eye.

In humans and most mammals and birds, the iris plural: irides or irises is a thin, annular structure in the eye , responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina. Eye color is defined by that of the iris. In optical terms, the pupil is the eye's aperture , while the iris is the diaphragm. The iris consists of two layers: the front pigmented fibrovascular layer known as a stroma and, beneath the stroma, pigmented epithelial cells. The stroma is connected to a sphincter muscle sphincter pupillae , which contracts the pupil in a circular motion, and a set of dilator muscles dilator pupillae which pull the iris radially to enlarge the pupil, pulling it in folds.

The structures and functions of the eyes are complex. Each eye constantly adjusts the amount of light it lets in, focuses on objects near and far, and produces continuous images that are instantly transmitted to the brain. The orbit is the bony cavity that contains the eyeball, muscles, nerves, and blood vessels, as well as the structures that produce and drain tears. Each orbit is a pear-shaped structure that is formed by several bones. The outer covering of the eyeball consists of a relatively tough, white layer called the sclera or white of the eye.

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Human eye , in humans, specialized sense organ capable of receiving visual images, which are then carried to the brain. The eye is protected from mechanical injury by being enclosed in a socket, or orbit, which is made up of portions of several of the bones of the skull to form a four-sided pyramid, the apex of which points back into the head. Thus, the floor of the orbit is made up of parts of the maxilla, zygomatic, and palatine bones, while the roof is made up of the orbital plate of the frontal bone and, behind this, by the lesser wing of the sphenoid.

The retina is a thin layer of tissue that lines the back of the eye on the inside. It is located near the optic nerve. The purpose of the retina is to receive light that the lens has focused, convert the light into neural signals, and send these signals on to the brain for visual recognition.

Anatomy of the Eye

Structure and Function of the Human Eye

Anterior chamber: The region of the eye between the cornea and the lens that contains aqueous humor. Bruch's membrane: Located in the retina between the choroid and the retinal pigmented epithelium RPE layer; provides support to the retina and functions as the 'basement' membrane of the RPE layer. Choroid: Layer of the eye behind the retina, contains blood vessels that nourish the retina.

The structures and functions of the eyes are complex. Each eye constantly adjusts the amount of light it lets in, focuses on objects near and far, and produces continuous images that are instantly transmitted to the brain. The orbit is the bony cavity that contains the eyeball, muscles, nerves, and blood vessels, as well as the structures that produce and drain tears. Each orbit is a pear-shaped structure that is formed by several bones. The outer covering of the eyeball consists of a relatively tough, white layer called the sclera or white of the eye. Near the front of the eye, in the area protected by the eyelids, the sclera is covered by a thin, transparent membrane conjunctiva , which runs to the edge of the cornea. The conjunctiva also covers the moist back surface of the eyelids and eyeballs.

Human eye , in humans, specialized sense organ capable of receiving visual images, which are then carried to the brain. The eye is protected from mechanical injury by being enclosed in a socket, or orbit, which is made up of portions of several of the bones of the skull to form a four-sided pyramid, the apex of which points back into the head. Thus, the floor of the orbit is made up of parts of the maxilla, zygomatic, and palatine bones, while the roof is made up of the orbital plate of the frontal bone and, behind this, by the lesser wing of the sphenoid. The optic foramen , the opening through which the optic nerve runs back into the brain and the large ophthalmic artery enters the orbit, is at the nasal side of the apex; the superior orbital fissure is a larger hole through which pass large veins and nerves. These nerves may carry nonvisual sensory messages—e. There are other fissures and canals transmitting nerves and blood vessels.

The anatomy of the eye

Беккер еще раз обвел глазами кучу вещей и нахмурился. Зачем АНБ вся эта рухлядь. Вернулся лейтенант с маленькой коробкой в руке, и Беккер начал складывать в нее вещи. Лейтенант дотронулся до ноги покойного. - Quien es. Кто он .

В международном аэропорту Далласа девушку встретил шофер АНБ, доставивший ее в Форт-Мид. В тот год аналогичное приглашение получили еще сорок кандидатов. Двадцативосьмилетняя Сьюзан оказалась среди них младшей и к тому же единственной женщиной. Визит вылился в сплошной пиар и бесчисленные интеллектуальные тесты при минимуме информации по существу дела. Через неделю Сьюзан и еще шестерых пригласили .

Говорит коммандер Тревор Стратмор. У нас в шифровалке человек взят в заложники. Быстро пришлите сюда людей. Да, да, прямо. К тому же у нас вышел из строя генератор. Я требую направить сюда всю энергию из внешних источников. Все системы должны заработать через пять минут.

Какая-то бессмыслица. Вначале был зарегистрирован нормальный ввод замка, в тот момент, когда она выходила из помещения Третьего узла, однако время следующей команды отпирания показалось Сьюзан странным. Две эти команды разделяло меньше одной минуты, но она была уверена, что разговаривала с коммандером больше минуты.

Я уполномочен заплатить вам за. На мгновение в комнате повисла тишина, затем Росио приоткрыла губы в хитрой улыбке. - Ну видите, все не так страшно, правда? - Она села в кресло и скрестила ноги.  - И сколько вы заплатите.

Все были в растерянности. - Ключ… - Ее передернуло.  - Коммандер Стратмор отправил кого-то в Испанию с заданием найти ключ. - И что? - воскликнул Джабба.  - Человек Стратмора его нашел.

Мысли его метались.

3 Response
  1. Alvin M.

    Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.

  2. Wendi S.

    Eyes. Structure and Function. The eye transmits visual stimuli to the brain for interpretation and, in doing so, functions as the organ of vision. The eyeball.

  3. Leonie L.

    Members of the animal kingdom use different strategies to detect light and focus it to form images.

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