Vision: How Our Eyes Develop
What you see is your world. And for infants and the very young, it’s a large part of their very small world. From infants first recognizing glance at their parents, to sensory input so crucial to brain development, eyes are important. Here’s how.
Your baby sees the world differently from you, literally.
Birth to three months:
Newborns can only focus 8-12 inches from their face.
Seeing only black, white, and grey.
Important moments in your baby’s world:
Recognize parents
and objects such as…
Toys
Mobiles
Bold Geometric patterns
Color vision begins to develop:
First Red
And Green
Then more subtle shades (like pastel colors)
Four to six months:
Depth perception and hand-eye coordination develops
This is crucial for eventually standing and walking
Important moments in your baby’s world:
Reach for…
Bottles
Toys
Begin moving towards…
Objects in the distance
8+ months
Children’s eyes increasingly resemble adult’s eyes.
Visual Acuity Over Time:
Retina already developed, yet babies’ nervous systems takes longer.
Analogy: Their “lens” is good, but the “film” isn’t developed.
1st month: 20/120 vision
4th month: 20/60 vision
8th month: 20/30 vision
(That’s 8 months of dramatic change)
Next few years: 20/20 vision
Vision Screening is less than a full eye exam, but can warn you of developing eye problems in your child.
Fact: 20/20 vision means that objects that are 20 feet away are as sharp as objects 20 feet away should normally be.
So What’s an Eye?
A Normal Eye:
Iris- the colored part of the eye that regulates the amount of light entering.
Lens-the clear part of the eye behind the Iris that focuses light onto the retina.
Pupil- the opening at the center of the iris. Adjusts in size to determine how much light enters.
Cornea-The clear outer part of the eye that focuses light into the eye.
Retina-The light-sensitive tissue lining the back of the eye. Converts light to electrical impulse.
Vitreous Gel- Clear gel that fills the eyeball.
Optic Nerve- Over 1 billion nerve fibers that carry electrical impulse from the eye to the brain.
Vs. The Non-Normal Eye
Vision problems tend to emerge from 18 months to 4 years of age.[3]
Two most common:
1.) 3-5% of children have a crossed or wandering eye
2.) 2-3% of children have uneven focus.
Developing a stronger and weaker eye:
Stronger eye=one that sees farther or focuses better
Weaker eye = the other eye
–If not corrected–
The brain starts ignoring the weaker eyes signal
Developing nerve connections to the stronger eye
And not the weaker eye
Leading to permanent vision loss by age 9-10.
Common eye ailments as we age:
Astigmatism: The cornea is shaped more like a football than a basketball.
Farsightedness: the cornea is too flat, and light focuses behind the retina.
Nearsightedness: The cornea is too curved, focusing light in front of the retina.
Presbyopia: the lens loses flexibility, losing the ability to bend and focus near and far. (This happens to everyone at some point during their life).
But no need to worry, it’s normal..[4]
30% of Americans are near-sighted
60% of Americans are far-sighted
and 75% of Americans use vision correction
Citations:
- http://www.ski.org/Vision/babyvision.html
- https://www.vsp.com/baby-vision.html
- http://www.webmd.com/eye-health/features/child-eye-and-vision-problems
- http://visual.ly/vision
- http://www.nei.nih.gov/health/eyediagram/
- http://www.durrievision.com/vision-for-a-lifetime/visual-and-eye-conditions-kansas-city/
