Hi

Does anyone know how can i calculate the CT of an oval lens?

like dia: e65/55 Power: +4.50 index: 1.5 minET: 0.5 Base: 6.00

and how does it work if i have decentration??

like dia: 55/65 Power: +4.50 index: 1.5 minET: 0.5 Base: 6.00

thanx