Design and fabrication of an active multifocal contact lens
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.
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
Figure 2: Recently developed technology at CMST can be
redesigned to achieve a switchable multifocal functionality without
negative side effects.