Originally posted by masterofpuppets
are humans eyes even open in the womb? or develped(im sure i messed up that word alot) enough to see yet?
Week 26: The fetus can now inhale, exhale and even cry. Eyes have completely formed, and the tongue has developed taste buds. Under intensive medical
care the fetus has a over a 50% chance of surviving outside the womb. (www.w-cpc.org...
Development of Vision
Vision, probably our most predominant sense after birth, evolves steadily during gestation, but in ways which are difficult to study. However, at the
time of birth, vision is perfectly focused from 8 to 12 inches, the distance to a mother's face when feeding at the breast. Technical reviews reveal
how extraordinary vision is in the first few months of life (Salapatek and Cohen, 1987).
Although testing eyesight in the womb has not been feasible, we can learn from testing premature babies. When tested from 28 to 34 weeks g.a. for
visual focus and horizontal and vertical tracking, they usually show these abilities by 31-32 weeks g.a. Abilities increase rapidly with experience so
that by 33-34 weeks g.a., both tracking in all directions as well as visual attention equals that of babies of 40 weeks g.a. Full-term newborns have
impressive visual resources including acuity and contrast sensitivity, refraction and accommodation, spacial vision, binocular function, distance and
depth perception, color vision, and sensitivity to flicker and motion patterns (Atkinson and Braddick, 1982). Their eyes search the environment day
and night, showing curiosity and basic form perception without needing much time for practice (Slater, Mattock, Brown, and Gavin, 1991).
In utero, eyelids remain closed until about the 26th week. However, the fetus is sensitive to light, responding to light with heart rate accelerations
to projections of light on the abdomen. This can even serve as a test of well-being before birth. Although it cannot be explained easily, prenates
with their eyelids still fused seem to be using some aspect of "vision" to detect the location of needles entering the womb, either shrinking away
from them or turning to attack the needle barrel with a fist (Birnholz, Stephens, and Faria, 1978). Similarly, at 20 weeks g.a., twins in utero have
no trouble locating each other and touching faces or holding hands!