The five senses are controlled by the brain, which is connected through nerve cells. When a fetus is growing, one of the first parts of the visual system to start developing is the optic nerve, a thick bundle of millions of individual nerve cells that will pass information from the eyes to the brain and vice versa.

During week 4 of pregnancy, cells from the developing brain tissue begin to form two optic nerves, one on each side of the head. Around the same time, other cells start developing into what will eventually become the lens of the eye, which helps babies focus on objects both near and far.

During prenatal development, environmental factors can significantly affect the development of the child. Almost everything the mother ingests, including food, liquid, and even medication, travels through the placenta to the fetus – anything the mother is exposed to in the environment affects the fetus. In patients with Diabetes Mellitus type 2 may play a role during pregnancy, although it is not quite clear. A teratogen is any substance or agent in the environment that can have a detrimental effect on a developing fetus. Various teratogens include drugs, alcohol, tobacco, and other environmental agents (http://courses.lumenlearning.com/boundless-psychology/chapter/prenatal-development/).

Prevention and early identification

• Around age 3½, kids should have eye health screenings and visual acuity tests (tests that measure sharpness of vision) with their paediatrician or family doctor.
• Around age 5, kids should have their vision and eye alignment checked by their paediatrician or family doctor. Those who fail either test should be examined by an eye doctor.
• After age 5, routine screenings should be done at school and the primary doctor’s office, and if symptoms such as squinting or frequent headaches occur. (Many times, a teacher will notice that a child isn’t seeing well in class.)
• Kids who wear prescription glasses or contacts should have annual check-ups by an eye doctor to screen for vision changes.
• Near-sightedness is the most common refractive error in school-age children; others include farsightedness and astigmatism:

Identification of eye problems

Signs that a child may have vision problems include:

• constant eye rubbing
• extreme light sensitivity
• poor focusing
• poor visual tracking (following an object)
• abnormal alignment or movement of the eyes (after 6 months of age)
• chronic redness of the eyes
• chronic tearing of the eyes
• a white pupil instead of black

In school-age children, other signs to watch for include:

• being unable to see objects at a distance
• having trouble reading the blackboard
• squinting
• difficulty reading
• sitting too close to the TV

Watch your child for signs of poor vision or crossed eyes. If you notice any eye problems, have your child examined right away so that the problem doesn’t become permanent. If caught early, eye conditions often can be corrected.

In conclusion – prevention is better than cure!