The growth of the eye in children
Dr. Orathai Chansanti, Corneal Ophthalmologist
The growth of the eye is more common in infants during their first 2 - 3 years. Eye changes and possible diseases can occur anytime. We, therefore should know when to take our children for visual acuity, so that we can improve their vision.
Size of the eye
During the first year, the growth of eyes is the most. The length of the eyeball is increasing steadily. The average newborn's eyeball is about 17mm. During the first year, the eyes are longer, up to 4 mm. At age of 2 - 5 years, the eye length is just 1mm. The last stage age 5 - 13 years, it would add only about 1 - 2 mm. By that time, their eye size will be the same as an adult’s, which is 24 mm. If the growth of the eyeball has changed, such as having unusual near or far vision, this may cause hyperopia or myopia.
The other factor that affect the vision is curve of the cornea and crystalline. After being born, lenses are very curved, with up to 52 diopters. In the first 6 months, cornea is getting flat and flatter. The capacity to refract light is down to 46 diopters and curve of cornea will decrease until it is same as the adult at age of 12 years ( in the refractive index at 42 diopters ). The lenses of eyes are vital organ, also affects the refraction of light before entering the eyeball. After birth, the average thickness of lens is 0.96 mm. This will reduce the thickness down to 0.52 mm at 6 months of age.
Changes in vision
As previously mentioned, changes in the eye is depending on the increase of length of the eyeball including changes in the curve of cornea. Babies typically suffer hyperopia approximately + 1.00 diopters. Eyesight will be very high when they are at 2 - 4 years of age, which is approximately +2.00 to +3.00 diopters of hyperopia. After that it will continue to decline to be the normal eye at the average age of 16 years. Generally, changes in each individual's eyes are slightly different. However, it was found that if children had myopia since early age before 10 years, they would have higher risk to be greater than -6.00 diopters myopic when growing up.
After we realize that eyesight will change during childhood, to have the problem fixed in this period is very important for their development. Good vision is the result when brain is well stimulated.