Method and system for determining personalized near addition value, lens with such addition

A lens for controlling myopia progression comprising:

• at least one surface with a personalized near addition value for a subject having progressing myopia, wherein
• the personalized near addition value is determined based on a plotted mathematical function between addition value (ADD) and the corresponding measured ratio of fusional amplitude (FA) and phoria (Ph) by determining a near addition value that provides a value for the ratio |FA/Ph| being equal to a set value,
• a measurement of the measured FA and Ph is made with at least one addition value on both eyes of the subject at a working distance, the addition value being the same for both eyes, the measured FA being measured, via a lens measurement device, based on a maximum horizontal prism value that indicates when the subject begins to have diplopia by holding the at least one addition value constant and changing a horizontal prism value until the diplopia begins, and
• the mathematical function is an inverse proportional function |FA/Ph|=a/(b.times.ADD+c), where a, b, c are constants optimized for each subject or is a linear regression function |FA/Ph|=d.times.ADD+e, where d and e are constants optimized for the subject.

A system for determining personalized near addition value for non-presbyopes comprising:

• a computer processor configured to perform:
• accepting an input of measured fusional amplitudes (FA) and phoria (Ph) with at least one addition value on a subject's both eyes, the addition value being the same for both eyes, the measured FA being measured, via a lens measurement device, based on a maximum horizontal prism value that indicates when the subject begins to have diplopia by holding the at least one addition value constant and changing a horizontal prism value until the diplopia begins;
• based on an addition value (ADD) and the corresponding measured FA and Ph, plotting a mathematical function of a ratio |FA/Ph| vs. ADD;
• and
• determining, based on the plotted mathematical function, a near addition value that provides a value for the ratio |FA/Ph| being equal to a set value, wherein
• the mathematical function is an inverse proportional function |FA/Ph|=a/(b.times.ADD+c), where a, b, c are constants optimized for each subject or is a linear regression function |FA/Ph|=d.times.ADD+e, where d and e are constants optimized for each subject, and the near addition value personalizes lenses for control of myopia of the subject.