Progressive Addition Lens for a Wearer

A process implemented by computer means for determining the optical surfaces of a progressive addition lens for a wearer, the process comprising:

• a prescription data providing step during which prescription data of the wearer comprising the prescribed addition are provided;
• an optical function determining step during which an optical function according to the prescription data is determined;
• and
• a surface determining step during which the surfaces of an optical lens having the previously determined optical function are determined;
• wherein the optical function corresponds to a virtual progressive lens having:
• a first vision zone corresponding to the portion of the progressive addition lens having the dioptric power for the first distance vision corresponding to the prescription data,
• an addition between the first vision zone and the near vision smaller in absolute value than the addition of the prescription data, and
• wherein for a pupil diameter of 4 mm the modulation transfer function is greater or equal to 0.1 over the range of spatial frequency comprised between 0 and 20 cycles per degree.

A process for manufacturing a progressive addition lens using a manufacturing device comprising the steps of:

• providing a lens blank;
• blocking the lens blank;
• and
• surfacing the surfaces of the lens blank as determined according to a process implemented by computer means for determining the optical surfaces of a progressive addition lens for a wearer, the process comprising:
• a prescription data providing step during which prescription data of the wearer comprising the prescribed addition are provided,
• an optical function determining step during which an optical function according to the prescription data is determined, and
• a surface determining step during which the surfaces of an optical lens having the previously determined optical function are determined,
• wherein the optical function corresponds to a virtual progressive lens having:
• a first vision zone corresponding to the portion of the progressive addition lens having the dioptric power for the first distance vision corresponding to the prescription data,
• an addition between the first vision zone and the near vision smaller in absolute value than the addition of the prescription data, and
• wherein for a pupil diameter of 4 mm the modulation transfer function is greater or equal to 0.1 over the range of spatial frequency comprised between 0 and 20 cycles per degree.