What are our eyes made of?

Visual receptors are cells on the retina. Most parts of the eye, such as the pupils, lenses, etc., are actually refractive systems. Light passes through the cornea and pupil and is refracted by the lens and collects on the retina, causing changes in the cone cells or rod cells on the retina, which cause impulses from the optic nerve and afferent them to the center.

The area where the optic nerve passes through the retina to the brain and has no photoreceptor cells, so it is called a blind spot.

Moisturizing of the eyes.

On the surface of the eyeball, there is a thin film of lubricating tears that constantly refreshes with the blink and keeps the eye moist. If the air is dry or you have been paying full attention, after about 10 seconds, dry spots will appear on the tear film, and the surface of the eyeball will become drier and drier. So under normal circumstances, you have to blink 10-20 times per minute.

When concentrating on reading or operating the computer dizzily, the blink frequency will be significantly reduced to about 5 times per minute. Due to the dryness of the eyeball, the cornea and eyelid are prone to abrasion when the eye is open and closed, which can cause dry eyes, fatigue, discomfort, inflammation and pain, and form dry eye syndrome. If left unattended, corneal ulcers and scarring can occur, eventually leading to vision loss.

The above content refers to Encyclopedia - Visual Receptors.

One of nature's most complex structural features, the human eye is so complex that it's hard to believe that it wasn't designed by a clever design. Based on scientific studies of the eyes of many different animals, biologists now understand that the eyes evolved from a simple light-receptor over a period of 100 million years. The function of the eyes is a bit like that of a digital camera, the eyes are open, and after the light source enters, there is a pair of bifocal lenses to focus, and at the same time, there is also a light sensing film to carry out light sensing.

The total number of binocular shots is manipulated by annular and radial musculature within the retina, which retracts and releases pressure, changing the size of the pupil. The first thing that comes into contact with the light source in both eyes is a hard, defensive membrane, the cornea. The light source then enters the lens, an adjustable structure that bends the light source and targets it at the macula of the fundus at the back of both eyes.

The macula under the eyes is covered with millions of photoreceptors. Each receiver has a melanin molecular structure that changes shape when it hits light, and then turns on an electrical signal that is transmitted to the human brain according to the nerve of the eye.

Let's take a look at the structure of the eye from the outside in: it is the sclera, this milky white hard membrane keeps the eyes spherical. The cornea, which covers the pupil and retina, is a hard, fully transparent membrane that protects vision and focuses on light sources.

The pupil is a hole that allows natural light to enter the back of the eyes.

The retina, the ring-shaped musculature within the iris, manipulates the size of the pupil to turn off in bright light, making it great in the dark. The ciliary body, a mechanism that surrounds the lens of the eye, manipulates the muscle tissue to change the shape of the lens of the eye. The lens, which is responsible for focusing the light source, changes the shape of the eye lens to blend in with objects far and near the eyes.

The fundus macula, the retina has a signal receiver that detects the light source, which is relatively highly pigmented, and the signal receiver can block the dispersion of the light source while ensuring a clear image. Blind spot, where there is no eye nerve and no indoor space for the light source signal receiver, leads to a natural blind spot in people's visual effects.

After the light enters the eye, it is imaged on the retina through the refraction of the lens, which allows the eye to see what they see; The structure of the eye is very complex, it is composed of cornea, aqueous humor, lens, glass balls, retina, etc.

After the light enters the eye, it will be projected on the retina, and you can ** something, the eye is composed of the cornea, lens, vitreous, retina, and optic nerve.

From front to back, the eye can be divided into cornea, lens, vitreous, retina, optic nerve. It is relatively easy to understand if the eye is compared to a camera, the lens is equivalent to the lens of the camera, and the retina is equivalent to the negative of the camera. The eye is the visual organ of the human body, including the eyeball, ocular appendages, optic pathways, and related vascular and nerve structures.

From front to back are the cornea, conjunctiva, sclera, iris-lens, vitreous humor-retina, optic nerve.

I see others have said that eyeballs include 1Eyeball wall: It is divided into the outer membrane (fibrous membrane), the median membrane (vascular membrane), and the inner membrane (retina).

Adventitia (fibrous membrane): It is divided into cornea and sclera.

Media (vascular membrane): It is divided into iris, ciliary body, and choroid.

Intima (retina): It is divided into iris, ciliary, and optic parts.

2.Contents: Divided into aqueous humor, lens, vitreous.

1. Sparkling eyes.

2. Red and glamorous clothes.

3. Sweet dim sum.

4. Twinkling stars.

5. The silver of the white flower evokes the flower.

6. Swarthy**.

7. Bright living room.

8. The garage of the black hole.

9. Green meadows. and coarse merging.

10, golden shiny **.

11. The red sun.

12, Qing Lingling's river bench calls for water.

13. The vast earth.

The human eye is nearly spherical in shape and is located in the orbit. The average anteroposterior diameter of a normal adult is 24 mm, and the average vertical diameter is 23 mm. The anterior end protrudes 12-14 mm outside the orbit and is protected by the eyelids.

The eyeball includes tissues such as the wall of the eyeball, the intraocular cavity and contents, nerves, and blood vessels.

The eyeball wall is mainly divided into three layers: outer, middle, and inner. The outer layer is made up of the cornea and sclera. The middle layer, also known as the uvea, is a pigmented membrane, which is rich in pigment and blood vessels, including three parts: the iris, ciliary body and choroid.

The inner layer is the retina, which is a transparent membrane and the first stop for the transmission of neural information formed by vision. It has a very fine network structure and rich metabolic and physiological functions.

The intraocular cavity includes the anterior chamber, the posterior chamber, and the vitreous cavity. The contents of the eye include aqueous humor, crystals, and vitreous. All three are transparent and, together with the cornea, are called refractive mediators.

It also includes the optic nerve, optic pathway, and ocular appendages. Ocular appendages include the eyelids, conjunctiva, lacrimal organs, extraocular muscles, and orbits.