摘要 |
The profile confers upon the lens a dioptric power having a progression that commences from a maximum of 10 dioptres at the centre, continues to 3.00 dioptres at 0.50 mm from the centre, continues further to -0.5 dioptres at 0.88 mm from the centre, thereafter remains parallel to the abscissa until 1.25 mm and then rises to two successive peaks of respectively 2.35 and 3.50 dioptres, after which it descends first to a value of -0.50 dioptres at 1.70 mm from the centre and then to -0.75 dioptres at 2.50 mm from the centre, thereafter remaining constant at about -0.75 dioptres to the end of the optical zone of the lens (Fig. 3). <IMAGE> |