Night blindness
Nyctalopia( NIGHT BLINDNESS)
Nyctalopia, commonly called as night blindness in the reduced ability of a person to see in dim illumination.
These problems are often worse just after a person is in a brightly lit environment. Milder cases may just have a harder time adapting to darkness.
This could be classified into 2 types
Progressive night blindness
Stationary night blindness
PROGRESSIVE NIGHT BLINDNESS
The progressive night blindness is where the ability to see in the dark reduces progressively with age. This happens in the disease called Retinitis pigmentosa (RP).
Retinitis pigmentosa (RP) is the most common inherited cause of blindness in people between the ages of 20 and 60 worldwide
The eye can be compared to the camera; the camera has a screen in which the image is produced. Similarly, the eye has a layer called Retina, which can be considered to the extension of the brain. The object that we see falls on the retina and is “sent to “the brain for the perception and recognition of the object.
But unlike the screen of the film, the retina has cells to improve the clarity in the day and night.
There are called rods and cones (together called as the photoreceptors)
Rods are responsible for the night vision and ability to detect motion peripherally.
Cones are responsible for the day light vision and Color vision ability.
In retinitis pigmentosa, the rods are affected. They degenerate progressively hence reducing the ability of the person to see in the dim illumination. the disease progress, the ability of walking straight without support reduces. Since the rods are responsible for our visual field, the person will not be able to see the surrounding objects while looking straight at something. The visual field of a normal person would be more than 120 degrees. That could be reduced to as much as 30 degrees or even lesser in RP.
Normal image A person with “RP”
As the disease
Nyctalopia, commonly called as night blindness in the reduced ability of a person to see in dim illumination.
These problems are often worse just after a person is in a brightly lit environment. Milder cases may just have a harder time adapting to darkness.
This could be classified into 2 types
Progressive night blindness
Stationary night blindness
PROGRESSIVE NIGHT BLINDNESS
The progressive night blindness is where the ability to see in the dark reduces progressively with age. This happens in the disease called Retinitis pigmentosa (RP).
Retinitis pigmentosa (RP) is the most common inherited cause of blindness in people between the ages of 20 and 60 worldwide
The eye can be compared to the camera; the camera has a screen in which the image is produced. Similarly, the eye has a layer called Retina, which can be considered to the extension of the brain. The object that we see falls on the retina and is “sent to “the brain for the perception and recognition of the object.
But unlike the screen of the film, the retina has cells to improve the clarity in the day and night.
There are called rods and cones (together called as the photoreceptors)
Rods are responsible for the night vision and ability to detect motion peripherally.
Cones are responsible for the day light vision and Color vision ability.
In retinitis pigmentosa, the rods are affected. They degenerate progressively hence reducing the ability of the person to see in the dim illumination. the disease progress, the ability of walking straight without support reduces. Since the rods are responsible for our visual field, the person will not be able to see the surrounding objects while looking straight at something. The visual field of a normal person would be more than 120 degrees. That could be reduced to as much as 30 degrees or even lesser in RP.
Normal image A person with “RP”
As the disease