Parents of blind infants need not miss out on something researchers call the voice/space event. This simply means that human infants are hard wired to turn their heads towards their mother's voice (to align the head for looking at a human face). The blind infant may not see the mother's or father's face, but the child will turn the head. This is the opportunity for the parent to take the child's tiny hand and brush it against their face as they speak to their child. This is as good as eye contact bonding and as powerful for parents.
A great amount of vision development goes on in the womb before the child can be ready to visually bond. After birth, a great amount of vision development continues to happen as the child grows toward adulthood. Taking the story back even farther, the remarkable ability to see is the result of thousands of years of evolution. It is also true that ontogeny recapitulates phylogeny, which simply means that the human embryo goes through all the phases of human evolution in the march toward birth. What we see in evolution, we also see in the womb.
The vision system goes through a developmental pattern as human beings age. The following paragraphs discuss developmental stages, and the impairments and functional implications of developmental disorders.
The vision system ages: it evolves in the womb; it grows and develops abilities through infancy and childhood; it weathers and adjusts to the hormonal storms of adolescence; and it gets old, just like all the other body systems. Many vision impairments develop before birth or at the moment of conception, if there are birth complications. Other vision anomalies occur during the rapid growth years, many are a playing out of genetic heritage. Aging brings characteristic, universal deteriorations to the vision system (loss of accommodation, cataracts, atherosclerotic changes, etc.). To have an overall understanding of vision, it is important to look at the developmental cycle in some detail.
During the year in utero, as the child grows from a one celled creature, to a baby about to be born, the eye evolves. The face develops (grows) from the sides (ears) toward the midline (nose, mouth). If developmental problems occur at this early stage, if the face does not "zip" shut at the midline, it is possible that the eyes might fail to develop at all (cleft face). This is very rare. Less rare is a condition in which the eyeballs themselves fail to zip shut at the midline resulting in what is called a coloboma. In this case, you get cleft lenses, cleft irises, and/or cleft retinas, with corresponding impairments to the various early vision systems (affecting the optical abilities of the eye, and/or early visual processing at the level of the retina).
Premature babies often have eyes not ready to see or process light. Retinopathy of prematurity can occur especially with very premature babies (usually under a pound birth weight).
Specific developmental cycles of vision must be understood, as well as the relationship to overall human developmental theory.
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