MadSci Network: Anatomy |
Dear Kai, Thank you for your interesting question about eye development. The eyes of a baby do appear enormous and a lot of people believe that humans are born with full-sized eyes. It is however not the case. The measure of choice for evaluating the size of the eyes is the antero-posterior length (the length from front to back), as it is the only optically significant dimension. This length averages 17.3mm at birth, and averages increase to 20mm at one year of age and 22 mm at three years of age. The eyes stop to grow between 8 and 13 years of age, at the average length of 23mm (Vaughan and Asbury, 1986; Fledelius and Christensen, 1996). The relative shortness of the eye at birth is compensated by a very spherical lens, which has a very high refractive power. As the eye grows in length, the lens grows new fibres around its periphery, making it flatter and diminishing its refractive power (Vaughan and Asbury, 1986). Neat interaction, isn’t it! References Fledelius and Christensen (1996), British Journal of Ophthalmology, 80(10), 918-921. Vaughan and Asbury (1986). General Ophthalmology (11th ed.) Lange: Los Altos, CA
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