*As water has a refractive index similar to the cornea, aqueous humour and vitreous humour, most refraction is carried out by the lens itself, which often has an extremely high refractive index. The lens is often extremely spherical, and accommodation is effected by moving it rather than distorting it. | *As water has a refractive index similar to the cornea, aqueous humour and vitreous humour, most refraction is carried out by the lens itself, which often has an extremely high refractive index. The lens is often extremely spherical, and accommodation is effected by moving it rather than distorting it. |