multifocal

Design and fabrication of an active multifocal contact lens

Problem Definition:

Human sight heavily relies on the accommodation power of the eye. By adapting the curvature of the intraocular lens, we are able to focus on both near as far objects. Apart from well-known ophthalmic disorders like nearsightedness and farsightedness, almost everyone will experience a decreasing accommodation power, which generally becomes noticeable between the age of 40 and 50. As a result, people cannot read text properly anymore at arm's length without some corrective optics. These corrective optics are either glasses or contact lenses that can focus both on near as on far objects. However, both multifocal glasses or multifocal contact lenses require a significant adaptation period and especially in the case of contact lenses, negative optical effect such as halos, blurring and a reduced contrast are present.

Figure 1: multifocal contact lenses simultaneously focus on multiple distances, leading to negative effects such as halo's, blurring and a reduced contrast.

Objectives:

Liquid crystal lenses are a new kind of electro-optical components that can change their focal distance by the application of a certain voltage. If such a technology can be integrated into a contact lens, the lens would be able to switch between different focal planes without the negative side effects of common multifocal contact lenses. Recently, CMST developed a technology to integrate a liquid crystal layer into a thin, spherically deformed polymer film. Although the initial goal was to develop a integrated display, this technology can be altered to serve as a liquid crystal lens. In this master thesis, the student has to redesign the liquid crystal contact lens technology so that it can switch between different focal planes. These lenses will be fabricated by the student in our cleanroom and optically characterized to quantify their focusing properties. If this thesis is chosen by two students, different approaches will be included and the specific goals will be broadened.

Figure 2: Recently developed technology at CMST can be redesigned to achieve a switchable multifocal functionality without negative side effects.

Movie of a working lens: http://www.youtube.com/watch?v=-btRUzoKYEA

Keywords:

 contact lens, multifocal, liquid crystal

Location:

Ardoyen CMST + at home.

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