Fifty-two right eyes of 52 myopic patients ( mean [ SD ] age , 21 [ 2 ] years ) with spherical refractive errors ranging from -0.75 to -8.00 diopters ( D ) and refractive astigmatism of 1.00 D or less were fitted with a novel experimental RGP ( ExpRGP ) lens designed to create myopic defocus in the peripheral retina .