For those who need glasses with two optical powers, bifocals have long been the only option. They are now accompanied by varifocal and trifocal lenses, but these are not very convenient, and not all patients can use them easily. Japanese researchers have recently introduced their new invention – sensor glasses that can shift focus in a matter of seconds, without fixed lens zones.As people age, their vision changes: it is gradually becoming more difficult to see objects that are close to you. This is called presbyopia and constitutes a part of normal changes associated with ageing. For those facing the problem, there are several options available. These include bifocals and their enhanced versions, trifocals and varifocal lenses. But all of them imply combinations of segments positioned in such a way that you can use one segment of your lenses for distance viewing, and another one for reading (i.e. looking at things close to you). This is not very convenient, and some patients find it hard to get used to wearing such glasses due to the field of vision being restricted. However, advances in technology enabled scientists to develop a new kind of lenses, which are capable of changing their properties with a touch of the finger. Meet high-tech glasses called TouchFocus, developed by a Japanese company specializing in advanced materials. These stylish glasses are not as simple as they look. The circuitry hidden in them allows its wearer to switch focus instantaneously, just by touching its sensor gently. Once you’ve touched it, the crystals within the lenses shift orientation, and you switch between two modes: the one for near viewing distance, and the one for far viewing distance. Changing focus merely by tapping a special sensor on the glass temple is easy and stylish. TouchFocus use a battery that can last up to 10 days, and after that you have to recharge it again. The new glasses have a wider field of vision, compared to conventional progressive lenses and bifocals. This enables its owner to wear one pair of glasses without restricting your vision significantly, as is the case with standard lenses. This revolutionary eyewear has a lot of science behind it. It uses liquid crystal lenses, in which crystals are embedded within two substrates, accompanied by a display with electrodes that can shift crystal orientation to change focus. It is non-tunable, though, which means it can switch between two modes but not fine-tune the focus.
The glasses come in different colours and frame shapes. As of this moment, they are available only in Japan and cost a bomb (around $2,500), so they are not going to become a common gift for grannies soon. However, they are likely to become cheaper over time (as it always happens after new advanced technologies emerge). Perhaps, one day the product will hit other markets outside Japan.
TouchFocus website – touchfocus.com
Progressive Lenses (No-Line Multifocals) – allaboutvision.com