Visual acuity is a bulky topic in the sphere of pediatric ophthalmology. Visual acuity is clearness of eyesight. It is interrelated with neural and optical aspects (functioning of the retina, the sharpness of its concentration, and the sensitivity of the particular part of the brain). A formation of vision is associated with the total formation of the body. The ability to see objects often wondered scholars. In the threshold of 19th century, exploration of the sight was made with the help of microscope. The ability to perceive colors clearly is in accordance with the formation of the visual cortex, coordination of the eye muscles and capacity to focus. Until these complex systems have matured, images, shapes and colors will appear blurry. The quantity of visual stimuli that a newborn gets has an influence on the speed of sight development. If babies feel a lack of visual stimuli, visual cortex cells reduce or function with pathology which might result in negative aftermath for eye coordination. At the age of 4 months, some infants’ eyes occasionally look misaligned. Though, after this period inward crossing that happens sometimes is not healthy.
It is well-known that the newborn sees objects upside down because its visual cortices do not recognize that images that reach the retina are inverted. According to Khurana (2007), the approximate visual acuity of babies is considered to be between 6/120 and 6/240. In general, babies possess poor vision and not a big ability to concentrate beyond 6 or 10 inches away. Infants cannot perceive color differences till 2 to 3 months of age. Kids follow moving things at 3 months of age and visual acuity amounts to 6/60. It is said that months that depth perception develops from 4 months.
Babies have the ability to see faces and very bright objects. They are born with side eyesight, and then are able to concentrate on a single object in the centre of vision. Infants are sensitive to the light. Between 3 and 4 months, a child focuses on little objects, for instance, toys.
The newborn children adore items with contrast (black and white, checkerboards, striped). Most kids distinguish complex shapes and patterns while getting older. It is useful to change contrasting objects. First, a kid got accustomed to an obscure and dark environment. It is a small wonder if an infant prefers several colors because it is natural for this age. Till 4 months a baby’s range of eyesight increases to several meters, and follows faster movements with its eyes.
Testing of visual acuity in children implies that an infant should be responsive to the environment, a positive blind response means good visual acuteness, and it changes rapidly during 3-4 months. It is easy to define accurately fixation conduct since the fovea centrali (a part of the eye that is in the centre of the area of retina) forms till 3 months. If a baby concentrates just with one eye, it generates abnormal development of another eye. There are some changes in the eye-sight of the newborn during 3-4 months of age. While 1 month concentration is central and constant, 3 months are characterized by vision with both sides and eye coordination.
There are various types of measurement of visual acuity in babies. These are preferential looking test, Catford drum test, hundred & thousand sweet test, lea paddle, Cardiff acuity card test, visually evoked response, opto kinetic nystagmus test.
Indeed, infants have a preference for what is familiar, observe the faces, distinguishes colors with the exception of blue, respond to movements, contemplate persons at a distance, recognize people on vision selectively, and change preferences for novelty. A good visual acuity is significant in order to develop visual memory of observed objects, accumulate visual information.
References
Khurana, A., & Khurana, A. (2007). Comprehensive ophthalmology (4th ed.). New Delhi: New Age International.
Roberts, J., & Duyan, K. (1972). Binocular visual acuity of children: Demographic and socioeconomic characteristics, United States. Rockville, Md.: U.S. Dept. of Health, Education, and Welfare, Public Health Service, Health Services and Mental Health Administration, National Center for Health Statistics.
Roberts, J., & Duyan, K. (1970). Visual acuity of children, United States. Washington, D.C.: U.S. Dept. of Health, Education, and Welfare, Public Health Service, Health Services and Mental Health Administration.
