Computing contact lens power for Ametropia which equal glasses lens power

In general for human eye which have Ametropia the patient usually use glasses for correction myopia and so hypermetropia. In this research compute contact lens power which was compute equal or equivalent glasses lens which uses the patient for your eye Ametropia .In this research makes mathematic modeling for human eye, this optical model a first explain the lens power glasses uses the patient for treatment myopia and hypermetropia , a second part for this opticalmodeling explain a power contact lens who uses the patient when your leave a bout a glasses lens . In hypermetropia condition the patient uses glasses lens power as equal to + 12 diopter this means that there is a needing for a need contact lens equal to +13.636, but for patient who uses glasses lens -12 diopter , the contact lens which equal to this glasses is -10.067diopter .In general in this work compute powers contact which equal to power glasses lens which begin from (+1to+20)diopter and so (-1to-20)diopter . Notice in this research when increase glasses lens power will increase contact lens power so a power contact lens always less than glasses lens power this for myopia ,but for hypermetropia contact lens power is always greater than glasses lens power .