Page 102 - The Indian Optician Digital Edition September-October 2021
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prescription being prepared in Luxexcel’s
VisionMaster™ Software. The original monomer
employed by Luxexcel was a liquid material,
called VisionClear.™ It has a refractive index of
1.53 and Abbe No. 45. The software is loaded into
the VisionEngine™ 3D printer, which creates
lenses by jetting tiny droplets of the UV-curable
resin onto the substrate and curing it with UV
radiation. This method produces lenses with
less material waste. It is envisaged that smaller
versions of this equipment will be developed
enabling ECPs to 3D-Print lenses in their own
practices.
There is a growing demand to merge vision
correction with other wearable technology. FIGURE 3 LUXEXCEL VISION ENGINE 3D
Combining these produces so-called smart PRINTING SYSTEM
glasses and is a huge untapped opportunity for
both consumers and the wearable technology functionalities, potentially even replacing the
industry. Through the use of augmented reality need for smartphones. To create smart glasses,
(AR), data can be presented on displays built into the two emerging trends of customising
spectacles or headsets. For example, one can prescription lenses and integrating technology
obtain directions when out walking or driving in can be combined.
a similar fashion to that provided by a ‘Satnav’, or Many forms of smart glasses send an image
superimpose instructions for the steps necessary to be overlaid on top of the image coming
to replace or repair an unfamiliar machine from the real world. To do this it is necessary
component, provide recipes and talking points to change the direction of light beams coming
for a presentation – all without holding a device from one side of the frame so that it ends up
or looking down at a screen.
in front of the visual axis. One way to do this is
3D Printing technology is the easiest solution by creating an optical surface that directs the
to produce lenses which combine a prescription light through the interior of the lens where it
correction with integrated embedded foils. encounters an embedded device, for example,
The foil is not a lamination but is completely a slanted diffraction grid that modifies the
encapsulated inside the prescription lens trajectory of light into the pupil. A unique
material. This method is ideal for the new feature of the 3D printing process of prescription
generation of prescription eyewear and smart lenses is that optical surfaces can be created
glasses. Other examples of smart spectacles not only on the front and the back but also on
include electrochromic lenses which activate at the side which allows the light source to be
the wearers demand by tapping the sensor on integrated with the front of the frame rather
the side of the frame. than in the temples.
Switchable power lenses might also be INCREASED PRESCRIPTION ACCURACY
constructed where there is a power change
across the whole lens or just in the lower part of A further development to be expected is
the lens in the form of a wearer activated bifocal an increase in the prescription and supply of
segment when near vision is required. lenses, not in quarter-dioptre steps, but in one-
hundreth dioptre power intervals. Free form
Spectacles have been passive devices for machining methods produce a surface finish
decades. With the integration of technology, which is so smooth that the surface can be
they would become interactive. The wearer polished immediately, the smoothing operation
will have one single product with multiple is eliminated and only some 8 different polishing
| SEPT-OCT 2021 | 98 LENS TALK
