When babies start to see: Stages of change
Many parents are particularly interested when infants begin to see.The vision in children has its own characteristics and is formed gradually.Each month a baby is a change in the structure and function of the visual system.
What is the structure of the eyes of the newborn
visual system of the newborn has some differences from the visual system of the adult.The structure of the organs of vision in the development of the human body is gradually changing, and this is particularly intense in the first year of life.
eyeball newborn shorter than that of an adult, about six millimeters.Because of this child is not seeing close objects, a condition called hyperopia Hyperopia - than it is fraught? .The optic nerve and the muscles that allow movement of the eyes, newborn perfect.Their immaturity - a physiological reason for that is normal for that period of strabismus Strabismus - how to find the cause? .
thickness of the cornea (the front of the fibrous membrane of the eye) in the newborn is slightly larger than that of an adult.The child she was heavily favored ahead of the shaft and separated from an underlying protein shell.In the first week of life the cornea due to a temporary edema Prevention and treatment of edema - it is important to understand the root cause of not entirely clear.Normally within a few days, this phenomenon takes place.
lens in children also has its own characteristics.It is a lens that can be compressed and cracking.With this look of a man can focus on objects at different distances.The lens - Transparent semi-solid mass, which is enclosed in a capsule.After the birth, he has an almost circular shape, but gradually, as the child grows its diameter increases and it becomes like a lentil seed.
In the center of the iris (iris) is a hole called pupil.In low light the latter expands and the bright - narrows, and thus controls the amount of light that reaches the retina.Coating of the iris depends on the amount of pigment therein.
Newborns in the iris contains little pigment, so the color of their eyes are usually blue.As a child grows thicker iris, and the amount of pigment therein becomes larger.
most difficult on the structure and function of the eye membranes considered the retina, which lines the inside of the eye.The retina consists of rods, cones and nerve cells.When this shell receives light, the rods and cones there is a special electrical impulses that the nerve fiber (optic nerve) is transmitted to the brain.The retina in infants and partially developed.
Features of the child for months
most rapid development of the visual system takes place in the first months of life.In the first two weeks vision newborn evaluated only at sensation of light.Under the influence of the last of such children and pupils narrowed eyelids closed.Instead, people they see only blurred silhouettes.A child at this age are not yet capable of visually recognizing the people around him.
visual acuity in a two-week baby is much lower than that of an adult.This is due to the fact that the retina is still evolving.The field of view of the child narrowed, so a newborn does not accept people who stand at his side.
- In the second to the fifth week of life the baby can fix his gaze on the light source.From the fifth week of the infant is already noticeable coordinated eye movement in the horizontal plane.But they're still not perfect.A child can detect slowly moving object and follow its movement only for a short time.Visual acuity remained low, and the field of view - sharp narrowing.The baby responds only to those items that are located in close proximity to him.
- the second month of life, the child may stare at the toys and keep track of their movements up, down, left and right.At this time, formed the first idea of three-dimensional objects.The infant prefers to consider the details of the persons of others, a variety of patterns and objects.
- With three months of the child can be monitored for items that move in all directions, at a distance of 20 to 80 centimeters.Between three to six months, the baby is already beginning to distinguish the finer details and parts of the surrounding objects.He looks from close-toys are on the far and back, while not losing sight of them.The child blinks at fast approaching the subject, sees its reflection in a mirror and finds the mother's breast.
- In the sixth month, the infant forms a visual representation of the distance, and it develops a three-dimensional perception.In the seventh month of life the child is interested in relationship to the surroundings and notice the smallest details of the situation.
- In the period from the eighth month of the year before the child is already able to perceive the object is not only entirely, but in separate parts.He is looking for objects if they suddenly disappeared from his field of vision, as early as this age realize that they still exist, but are in a different place.Visual acuity increased even more.
- in the range from one to two years the child is celebrated almost complete consistency between the movements of the eyes and hands.He understands some gestures, able to observe how older children or adults draw or write.For four years in a child's eyesight is almost reaches the level of adults.
Since the visual analyzer in newborns is very poorly developed, the child immediately after birth does not distinguish colors.The ability to distinguish between them appears in the period between two and six weeks.First, the child learns to distinguish between red and yellow, and later - green and blue.Color vision ends formed about four years.
anatomical structure of the visual system of the newborn differs from that of adults.Each month the child's vision improved and gradually reaches the adult.