Multi-focal AR Contact Lenses Work for Both Near and Far

As we age, reading up close often becomes difficult. An eye specialist may suggest trying a near-vision contact in one eye, and a far-vision power in the other. A similar near/far dichotomy presents itself in the field of augmented reality (AR), where the need to simultaneously image a glasses-mounted screen while navigating in the larger environment presents a challenge to both users and designers.

Relating to this time last year, ExtremeTech reported on a contact lens system known as the iOptik, that was being developed as part of a joint effort between the US Department of Defense and a company called Innovega. A working prototype of their system has now been developed, and new competitors have also emerged to give them a run for their money.

The idea behind the iOptik, is that the contact focuses foreground light, like that from a nearby monitor, onto the center of the pupil. The background light is focused on the surrounding (annular) regions of the pupil. This resembles currently prescribed multi-focal contact lenses, which seem to work quite well — only these guys are just a little more extreme in the separation of the two fields.

The image is projected directly onto display components that are integral to a pair of special glasses. Superimposing full-field 3D virtual images, which would be particularly enticing for the gaming world, would be seamless with such a device. Interaction with avatars would take place in the whole user space rather than just on a limited screen.

Other approaches to AR, like that taken recently by The Center of Microsystems Technology actually embed a curved LCD into the contact lens. The potential applications for a system like this which also might also use embedded wireless technology would be astounding, however only crude versions of both are current feasible.

An important consideration for all the contact-based products will probably be the user feel of the lens. Nobody wants to be fussing around sliding a semi-rigid lens out of the way to read a menu in a dark restaurant for example. Another possible concern with the contact is that the tiny “lenslets” responsible for creating the short (1.25cm) center focus area, also have a filter layer that excludes all non-polarized light. The annular region, by contrast, excludes linearly polarized light. At night time, the effect of blocking a significant fraction of the incoming light will undoubtedly be noticeable. Devices like the iPad, which emit polarized light from their LCDs, will appear black when held in certain orientations due to the polarization filters. These effects do need to be taken in account when using the lens, but in the larger scheme of things, they appear to be minor concerns on a great new product.

Source: extremetech.com