Working of Eyes-
So at first talk about the working of eyes in very short .The light coming from an object enters the eye through cornea and pupil. The eye lens converges these light rays to form a real, inverted and diminished image on the retina. The light sensitive cells of the retina gets activated with the incidence of light and generate electric signals. These electric signals are sent to the brain by the optic nerves and the brain interprets the electrical signals in such away that we see an image which is erect and of the same size as the object.
The retina contains two types of photoreceptors, rods and cones.
The rods are more numerous, some 120 million, and are more sensitive than the cones. However, they are not sensitive to color.
The 6 to 7 million cones provide the eye's color sensitivity and they are much more concentrated in the central yellow spot known as the macula. In the center of that region is the " fovea centralis ", a 0.3 mm diameter rod-free area with very thin, densely packed cones.
What is blindness –
When a body lost the the power of interpretation of image signal due to any reason like unavailability of signal or very weak signal or unablity of tranfer of the signal , then this condition is called 'Blindness'.
So Why People get blind -
There can be many reason for blindness. Any failure
in the whole pathway or any part of eye object can make a person blind.
Most common deices of eyes -
Age-related macular degeneration (AMD) is a disease associated with aging that gradually destroys sharp, central vision.
Central vision is needed for seeing objects clearly and for common daily tasks such as reading and driving. AMD affects the macula, the part of the eye that allows you to see fine detail. AMD causes no pain.
Retinitis Pigmentosa (RP) is an inherited eye condition affecting initially the mid peripheral portion of the retina.
Initially, a person with RP may complain that their vision is poor at night ("nightblindness"). Peripheral (or side) vision gradually decreases and eventually is lost while central vision is usually preserved until late stages of the disease.
A cataract is an opacity (cloudiness) within the lens. Most cataracts are related to aging and are very common in the elderly population.
In the surgical treatment of cataract, the lens inside the eye is removed and replaced with a clear artificial lens.
Diabetic retinopathy occurs as a result of uncontrolled blood sugar associated with advanced diabetes and if left untreated, can cause blindness.
To date, there are no treatments for either AMD or RP.
Do We Have only Bad News?
Off course not!!! I am not here to tell you to tell you about the problem …......I am here to tell you some solution. It was just to give you a feeling that how big problem we are tying to solve. So in the next part of this post I will tell you about a great effort to solve most of these problems and about the 'Ray of Hope' for mankind.