• Universitat de València
• Universitat Politècnica de València
• AJL Ophtalmic, S.A.

• Juan Antonio Monsoriu Serra
• Arnau Calatayud Calatayud
• Laura Remón Martín
• Fernando Giménez Palomares
• Juan Luis Rojas Salegui
• Eva Larra Mateos
• Pedro José Salazar Salegui

The main disadvantage of presbyopia, caused by the inability to focus on near objects, is the dependence on the use of near glasses. Currently, existing contact lenses for the correction of presbyopia provide wearers with acceptable vision for 80% of daily activities. However, they still have limitations in certain circumstances. Most of the current proposals are bifocal in nature. Current models, even those designed to fit alternating monovision, have preset focus positions that allow very little design flexibility, providing a quality of vision that is not optimised for intermediate distances. It is therefore necessary to develop contact lenses that act more advantageously in these circumstances and are multifocal in nature, improving vision at all distances.

The contact lenses developed - based on aperiodic geometries and with a non-serrated profile - achieve better performance than conventional bifocal lenses. This is due to their novel design that allows the focus positions to be tuned to the set of construction parameters used. The distinguishing feature of these new designs is the way in which the different concentric annular zones are arranged in a non-periodic distribution. Thus, with this type of lens, it is possible to design contact lenses which, although they can be constructed in a similar way to conventional bifocals, can produce true multifocality and consequently good quality of vision not only at near and far distances but also at intermediate distances.

The main application of the technology is in the healthcare optics sector for the design of multifocal lenses, both contact lenses and intraocular lenses.

The main advantages provided by the invention are:

• Lenses with aperiodic geometries generate a sharper image at all distances as they are multifocal in nature.
• The lenses generate images with fewer halos, as they have less chromatic aberration due to the overlapping of foci.
• Less dependence on pupil size, which facilitates the adaptation process, due to the large depth of field obtained with the lenses.
• Increased wearing comfort of lenses that do not have a saw-tooth profile.
• The manufacturing equipment required is the same as that used for conventional contact lenses.

• Patent granted