habari wadau, mimi nina matatizo ya macho kitaalam very short sighted- high myopia keratucones kiasi cha kwamba siwezi kusoma au kuona fasaha bila msaada wa miwani yenye lenz nene....kwa kweli tatizo hili limeniathiri sana kisaikolojia hasa kujiamini, je kuna dawa/njia/vyakula/mbinu zozote naweza kufanya kuongeza uwezo wa kuona wa macho yangu, naomba michango yenu wadau natanguliza shukran
Mkuu, nilikuahidi ningekuletea maelezo juu ya uhusiano uliopo kati ya kushuka kwa kiwango cha maji mwilini na kushuka kwa uwezo wa macho, kama nilivyokiri mwenyewe binafsi kuwa ni maji ndiyo yalinisaidia kuondokana na matatizo ya macho, nakuletea na wewe notisi hizi zisome na uzielewe, nimeshindwa kuzitafsiri kuwa za kiswahili mwenye kuweza kufanya hivyo nitamshukuru.
THE EYE
The eye is a direct extension of the brain. It has been developed to process light. It translates the reflections of light as it shines on objects. It converts light pulses to nerve pulses, giving us the ability to see things. Light consists of high-energy photons that travel at the speed of 186,284 miles per second.
Evolution of the Eye as an Organ of Sight.
There are single-celled animals that possess photosensitive yellow pigment patches in their body. They can tell the direction of light from its action on the pigment. Higher up in the animal kingdom, such as in various types of worms and some shellfish, the pigmented area is held in clusters of pits or cups in their skin. These can better recognize the direction and intensity of light that enters the cup on the side of the light.
In certain other animal species, the photosensitive cups become deeper. The deepness of the cup causes the opening to become small. The smaller opening allows only a narrow band of light to hit the sensitive pigment at the back of the cup-very much like a pinhole camera. This type of eye, even without a lens, is more capable of producing sharper images than the earlier versions. Some types of squid-like marine species have this variety of eyes. In the next stage of development, we come across the photosensitive cups with a translucent membrane covering the cup.
The human eye employs the same principles as photosensitive cups, but has developed sophistication of design to suit our present-day needs.
THE HUMAN EYE
The eyeball consists of an outer firm fibrous white shell that is called the sclera. In front, this shell becomes translucent and is called the cornea. At the back, the optic nerve and the optic artery and veins pierce the shell. The artery enters the eyeball, and the nerve and the vein leave it.
Behind the transparent cornea lies the colorful iris, and behind that the lens. The lens and the iris are held in a combination of muscle and fibrous membrane. They partition the cavity of the eye into an anterior chamber and a posterior chamber. At the junction of the clear cornea and the white outer shell there is a drainage canal called the canal of Schlemm. This canal acts like a vein that drains the excess fluid from inside the eye. The fluid pressure, created by pumping water into the eye, is essential to keep it firm and round. The canal of Schlemm is designed to balance the pressure inside the eye by monitoring the low of excess water out of the chambers of the eye.
Inside the eye at its back, and to a certain extent to the sides of the eye, two other layers are attached to the firm eyeball shell. One layer, called the choroids layer, consists of blood vessels and pigment. The other layer is called the retina, and is made of photosensitive cells and their nerve filaments.
The retina contains two main types of photosensitive cells. One variety is the ROD cell and the other is the CONE cell. Rod cells only see black, white, and shades of grey. There are about 7,000,000 rod cells in each eye. Cone cells are sensitive to colored light. There are between 100,000,000 and 140,000,000 cone cells in each eye. In other words, each eye contains between 107,000,000 and 150,000,000 photosensitive rod and cone cells.
The fluid inside the two chambers of the eye not only maintains the size and shape of the eyeball, but also bathes the lens and the nerve cells lining the inside of the eye. The cavity in front of the lens contains aqueous humor. It is clear and translucent to light. The cavity behind the lens contains vitreous humor, which is slightly thicker in consistency but is still completely translucent to light. There is a constant low of water through these cavities. The excess water gets drained through the canal of Schlemm. This canal is situated in the wall of the eye at the junction of the sclera and the edge of the cornea.
Dehydration can alter the physiological balance inside the eye and be responsible for some types of visual loss. It can cause the following:
1. Glaucoma.
Maintaining the normal shape of the eyeball is vital. In an attempt to maintain the pressure inside the eye during dehydration, the drainage canal contracts and the pressure in the Eyeball rises, sometimes causing pain. This is called glaucoma.
2. Cataract.
Insufficient low of water through the chambers means that toxic waste is not washed away from the lens tissue. Excess toxic waste brings about a change in the consistency and inner structure of the lens. This change is called a cataract.
3. Vitreous Detachment.
The humor in the back chamber of the eye should be constantly refreshed, and the toxic waste from the cell lining of the eyeball should be cleared away. Comparative dehydration causes a change in the refractive properties of this fluid. At this stage of dehydration of the humor, the loss of sight can be reversible. If dehydration continues, the vitreous humor in the back chamber might harden and separate from the nerve layer of the eye. This is called a vitreous detachment. It is one of the major causes of partial blindness. It may not be reversible.
4. Uveitis.
In an attempt to bring more circulation to the eye and force water into the eyeball, the vascular bed under the nerve layer might open up more than is normal and cause an edema under the nerves. This inflammatory process that affects the vitreous humor is called uveitis. In its early stages, this is a reversible condition if dehydration of the body is corrected.
5. Multiple Sclerosis.
Another kind of dehydration-produced blindness can involve the optic nerve. Multiple sclerosis is an inflammatory condition that is produced by extreme dehydration of the body that has extended to the wall of the nerve tissue. It can at times involve the eyes, but is more often seen in the nerves of the spinal column.