Blindness is the inability to see images, shapes, objects or light. Blindness can either be total or partial.
A total blindness occur when one can't see anything at all. While a
partial blindness occur when one only have the abilities to see things
faintly or finds it difficult differentiating between shapes or objects.
What are the symptoms of blindness?
A complete blind person cannot see nothing at all. But a partially blind person might experience the following symptoms:
. Cloudy vision
Cloudy vision occur when an object is obscure or when it appear "milky". It is usually the symptom of a specific condition known as cataract. Cloudy vision is also similar to blurry vision and both can be a symptom of a more severe eye defects if they occur simultaneously.
. Visual Agnosia
Visual Agnosia is the process whereby a person finds it difficult differentiating or understanding visual shapes and objects. It is usually a problem of the brain and can occur even when the eyes are functioning effectively. The brain finds it difficult interpreting what shape or object the person have seen.
. Poor night vision
There are two major cells in the eye that are responsible for vision; cone cells and rod cells. The cone cells are sensitive to lights and colors, they help us to see during the day and can help us differentiate between colors. While the rod cells are cells that are sensitive to dim light, thus, they help us to see at night even when there are no much light in the environment.
Even when you are not a nocturnal animal, you should at least be able to see things a bit at night because of your rod cells. But when you find it difficult seeing things at all except when there is light, it actually means you have a poor night vision, which could explain that your rod cells are not effective.
. Tunnel vision
This is a type of vision whereby you see objects only when placed at the center of the field of view. For a person with a tunnel vision, the eye finds it difficult covering different angles when viewing a particular object.
What causes blindness?
The following eye diseases and conditions can cause blindness:
Glaucoma is a "neuron degenerative disease" that occur to the optic nerves, nerves that help to transmit visual impulse from the eyes to the brain. When this nerves are defective, visual information can no longer be sent to the brain for interpretation. Since the brain is the center of sight, the person involved tend to go completely blind because the brain is not having any visual information to process.
. Macular degeneration
disease destroys the part of the eye that enables you to see in
details. It results in a blurred or no vision in the center of the
visual field, majorly common in adults. Although this does not usually
result in a complete blindness but can make the sufferer finds it
difficult recognizing faces, reading, driving, or perform other
activities of daily life.
is a disease that causes cloudy vision. It make sights appear milky to
the eyes. They’re more common in older people and can usually be treated
. A lazy eye (Amblyopia)
Amblyopia is a visual developmental disorder in which the vision through one eye fails to develop properly in early childhood. The deficit is not in the eye itself but in the visual areas of the brain. It can make it difficult to see details. It may also lead to vision loss.
. Optic neuritis
neuritis is an inflammation that occur in the optic nerves, nerves that
carry messages to the brain. Pain and temporal vision loss are the most
common symptoms of the disease. It is different from glaucoma because
the optic nerves are not completely destroyed unlike glaucoma disease.
. Retinitis pigmentosa
Retinitis pigmentosa is a rare, inherited degenerative eye disease that occur in the retina. Although it does not result in a permanent blindness. Symptoms often begin in childhood. Symptoms include decreased vision at night or in low light and can also cause tunnel vision. There's no effective treatment for this condition but wearing sunglasses may help protect remaining vision.
Blindness is also a potential complication if one have diabetes or a stroke. Other common causes of blindness may include:
. birth defects
. eye injuries
. complications from eye surgery
What causes blindness in infants?
The following conditions can impair vision in infants:
. Infections, such as pink eye
. Blocked tear ducts
. Strabismus (crossed eyes)
. Amblyopia (lazy eye)
. Ptosis (droopy eyelid)
. Congenital glaucoma
. Retinopathy of prematurity (ROP), which occurs in premature babies when the blood vessels that supply their retina aren’t fully developed
. Visual inattention, or delayed development of your child’s visual system