MODEL – I ( Model Eye For Indirect Ophthalmoscopy & Retinoscopy ) Model-i is an ophthalmic teaching device used for practicing indirect ophthalmoscopy and retinoscopy. Normal & abnormal retinal structures are painted inside the eye.
The retina is located in the posterior segment and forms the innermost boundary among the other major layers of the eye that include the vascular choroid and the fibrous sclera.
Eyes are organs of the visual system.
eyeball. noun. eye·ball ˈī-ˌbȯl. : the more or less globular capsule of the vertebrate eye formed by the sclera and cornea together with their contained structures.
The retina is a complex part of the eye, and its job is to turn light into signals about images that the brain can understand.
As the cornea bends light when it enters the eye, the brain receives images that are upside down so it turns them the right way up when it processes the information.
Green is considered by some to be the actual rarest eye color in the world, though others would say it's been dethroned by red, violet, and grey eyes. Green eyes don't possess a lot of melanin, which creates a Rayleigh scattering effect: Light gets reflected and scattered by the eyes instead of absorbed by pigment.
Astigmatism means your eye is shaped more like a rugby ball than a football, so light is focused at more than 1 place in the eye. This can cause: blurred vision. headaches. eye strain (you may notice this after concentrating for a long time – on a computer, for example)
There are six main eye shapes — round, monolid, hooded, downturned, upturned and almond — and they're all fabulous in their own way.
Your eyes are organs that allow you to see. Many parts of your eye work together to bring objects into focus and send visual information to your brain.
The eye is made up of three coats, which enclose the optically clear aqueous humour, lens, and vitreous body. The outermost coat consists of the cornea and the sclera; the middle coat contains the main blood supply to the eye and consists, from the back forward, of the choroid, the ciliary body, and the iris.
Damage to the retina often leads to vision loss. Medical experts explain that when the retina is injured through disease or an accident, blood vessels are affected. The veins carry neurons between the optic nerve and the brain. When they are damaged, neurons die, and the brain doesn't receive visual information.
The retina is made of two parts, the macula and the peripheral retina. The macula is in the center of your retina and processes most of what you're directly looking at. The peripheral retina fills in the parts of your vision at the edges of your visual field (your peripheral vision).
Cover one eye. Hold the grid about 10 inches away from the eye you are testing. Look at the center dot keeping your eye focused on it at all times. While looking directly at the center, and only the center, be sure that all the lines are straight and all the small squares are the same size.
Eyebrows help shield your eyes from bright light. Eyelids close to keep harsh light and harmful objects out. Eyelids also keep moisture in. Eyelashes help catch dust and derbis before they get into your eyes.
The front part of the eye is filled with a clear fluid (called aqueous humor) made by the ciliary body. The fluid flows out through the pupil. It then reaches the eye's drainage system, including the trabecular meshwork and a network of canals.
The eye itself is made of 7 general components that all work together to keep us seeing well every day.
Yes, natural purple eyes are possible. There are many different shades of blues and greys out there and many in-between colors. Although very rare, some people's natural pigmentation can even be violet or purple in color.
We found that green is the most popular lens colour, with brown coming in a close second, despite it being one of the most common eye colours. Although blue and hazel are seen as the most attractive eye colours for men and women they are surprisingly the least popular.
Of those four, green is the rarest. It shows up in about 9% of Americans but only 2% of the world's population. Hazel/amber is the next rarest of these.
We are 3D creatures, living in a 3D world but our eyes can show us only two dimensions. The depth that we all think we can see is merely a trick that our brains have learned; a byproduct of evolution putting our eyes on the front of our faces.
It may seem that way, but it is impossible. It is believed that the human brain is incapable of “creating” a new face. Every person you dream of has been someone you have either known personally or merely came across looking through your friend's Facebook photos.
Your eyes can provide clues linked to Alzheimer's
A recent British study shows that your eyes might provide clues to your brain health: specifically, certain changes in your retina have been associated with Alzheimer's disease.