Cosmetically, the sunglass frame should balance the child’s face. Approximately one-third of the face should be visible above the upper rim, the sunglass frame should cover one-third of the face and one-third of the child’s face should be visible below the sunglass lower rims.
The sunglass frame should be as wide as the widest part of the face. If the sunglass is too narrow, it will look too small, not offer adequate sun protection and the face will appear too full. A sunglass frame that is too wide may be uncomfortable, make a narrow face appear narrower and overwhelm small features
Lens colour and type
Because of its absorptive effect on blue light and ultra violet (UV) radiation, brown lenses also are beneficial. As more research documents the damaging effects of blue light, the need for a brown lens becomes increasingly evident. Children at higher risk for macular degeneration (parents with family history) may also benefit from a golden-brown photochromic lens. An absorptive value of at least 70 percent is also recommended for all brown lenses used on children. Grey lenses offer better colour discrimination than brown coloured lenses … and UV their absorption is close to that of brown lenses
Photochromic lenses present the most practical and least obstructive method of protecting young eyes during the course of a normal day. On a dull day, they will absorb the less obvious radiation … and when the sun comes out, the lenses will darken as the intensity of light – and consequently UV radiation – increases. Children will not normally change their regular eyewear to prescription sunglasses as the events of the day change – and so photochromic lenses will offer the best practical solution to sun eye protection.