If you have three contacts for monovision, you need this invention!
As a person ages, the lens inside his/her eyes loses elasticity and is no longer able to focus on images, such as printing, up close. Traditionally, this condition, called presbyopia, has been corrected by wearing reading glasses, or for those people who also need correction for distance, by bifocal lenses. Recently, some people have opted to correct the vision surgically or non-surgically in their non-dominant eye for reading and in their dominant eye for distance. This approach to correction is often called monovision and can grant the person a temporary "reprieve" on needing separate reading glasses. (The eye continues to change, and so the correction is not permanent.)
In a non-surgical approach, the person typically corrects his/her dominant eye with a contact lens optimized for distance and his/her non-dominant eye with a contact lens optimized for reading. The advantage to this is that the person is able to switch easily between distance and up close activities. The disadvantage is some loss of depth perception and vision optimized neither for up-close nor distance.
The solution to this suboptimization is for the person to have three contact lens. Two lens are optimized for distance, call these lenses "L" and "R" for "left" and "right" eyes, and one lens, dubbed "M," provides for monovision. This approach allows the person to match his/her vision to the planned activities and obtain optimal vision during a given time period. For example, the person attending a football game would put in the "distance" lens of "L" and "R" to see best the action on the field. A person attending the symphony, on the other hand, might wear the "M" lens (in the appropriate eye) in order both to see the performers and to read the program.
Most contact cases are designed for two lenses, labeled simply "L" and "R." Unfortunately, therefore, people taking advantage of monovision end up with two separate cases and, when switching lenses, need to remember in which L-labeled or R-labeled case the "M" contact resides. They also run the risk of spreading infection between eyes by switching lenses between slots in the case, run the risk of leaving home without both cases, and end up with a wasted slot. This invention solves these issues.
The monovision case has three slots, as described above. The "L," "R," and "M" on each of the slots is raised such that a person can distinguish them by touch, and they may also be molded in braille. The inside of the slots has "grooves" to prevent contact lenses from adhering to the case via suction, and has a "divot" at the base to make sure contact solution, if used, is able to get underneath and around the lens.
The monovision case required no new materials or processes, but does require a retooling of molds from two-lense to monovision models.