Charlotte Lozier Institute

Phone: 202-223-8073
Fax: 571-312-0544

2776 S. Arlington Mill Dr.
Arlington, VA 22206

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Eye Formation

Dive Deeper
Baby's eyes form from the interaction of nervous tissue, outer tissue called ectoderm starting at 6 weeks. At birth, the newborn is born able to see, but with such low visual acuity that she is legally blind. Visual experience outside the womb helps the visual system finish developing. (Image Credit: Science Source)

The eyes begin forming 22 days after conception, also known as 5 weeks and 1 day gestation.1 Tissue from the developing brain pushes forward towards the face to form an optic cup and the beginnings of the optic nerve, which will connect the eye to the brain. The optic cup becomes the back of the eye, called the retina, which turns light energy into neural signals. The front of the eye, including the cornea and the lens, both form from the surface tissue. Instead of becoming skin, chemical messages from the optic cup turn these structures into transparent tissue. In the eighth gestational week, more surface tissue interacts with the cornea and lens to form the embryo’s eyelids.2 Interestingly, the embryo’s eyelids actually fuse together around 10 weeks, and only reopen around 20 weeks.3

The front and back of the eyeball fuse together by week 10, and muscles start moving the eyes by week 12.4 Eye movements can be detected by ultrasound, and can reveal whether a baby is awake, asleep, or dreaming.5

Most infants are born with light blue or gray eyes. A baby’s eye color finalizes between 6 and 12 months old. The color is determined by the distribution of melanin in the iris. Melanin is the same pigment that gives skin its color. If the melanin stays at the back of the iris, then the eye will be blue. If the melanin is found all over the supporting tissue in the iris, then the eye will be brown.6

Major milestones in eye development:

Age Milestone
Week 6 Lens placode and optic vesicles form.7
Week 8 Pigments developing in retina.8
Week 9 Eyelids form.9
Week 10 The eyeballs finish forming.10 Eyelids fuse together.11
Week 11 Rods start forming.12
Week 12 First eye movements detected.13
Week 18 Layers of the retina start forming.14
Week 20 Rapid eye movements begin. The eyelids open again.15
Week 25 Eyes start functioning.16
Week 28 First fetal responses to light.17
Week 29 Fetal pupils respond to light.18
Sperm-egg fusion