Presbyopia – effect of refractive index

The causes of presbyopia are discussed in terms of the possible influences of the optical parameters of power: the shape as well as the refractive index variations. From this and other studies it would appear that with age the human lens becomes more curved and yet the refractive index does not decrease correspondingly to explain the loss of accommodative power. A synchrony between growth and refractive index distribution is advanced as a possible explanation for the ‘lens paradox’.