Though eyeglasses that react to light have been available for decades, researches have had problems developing contact lenses with similar capabilities. The previous attempts were largely unsuccessful because it is extremely difficult to apply the special dye uniformly to the surface of a contact lens.

The researchers from the Institute for Bioengineering and Nanotechnology (IBN) in Singapore used a new polymer that makes it possible to embed dyes in the material of the lens itself, so it is not necessary to put it on the surface of the lens. What is more, dyes may be distributed uniformly, which in turn allows manufacturers to embed more dye molecules, resulting in enhanced sensitivity to light and a faster reaction. The latter has been increased so dramatically that they may react ten to even twenty times faster than photochromic eyeglasses. This is especially important for drivers, who need clear vision at all times.

Having successfully tested the material on rabbits, the researchers are now preparing to test the lenses on humans. It is, however, unknown when the new lenses will be ready for mass production.

In the Western World, glaucoma remains the second most common cause of blindness. It affects the optic nerve by increasing intraocular pressure and depriving the nerve of nutrition and oxygen. As a result, the nerve gradually atrophies and the patient becomes permanently blind. So far, the only treatment for this disease consists in lowering the elevated intraocular pressure, either surgically or with the use of special eye drops. Both these methods require regular follow-up exams, which is time consuming and inconvenient for patients. Another issue is the fact that changes in intraocular pressure may be sudden and might not show during examinations.

New contact lenses recently approved for sale in Europe are a breakthrough in the treatment and monitoring of glaucoma. They are a silicone hydrogel lens with an embedded microprocessor measuring changes in eye pressure and transmitting the results to a receiver. This way eye care practitioners will have all the data necessary for effective treatment and will be able to adjust it before irreparable damage to the optic nerve occurs.

The system, called Triggerfish, should also be approved by the American Food and Drug Administration by late 2011.

Hyperopia, also known as farsightedness, is typically a genetic condition causing blurry near vision as a result of the fact that a person’s eye is too short or the cornea is too flat. Typically, farsighted patients wear glasses, contact lenses or undergo laser surgery. However, the latest development in contact lens technology may change that dramatically.

Jaume Pauné from UPC-Barcelona College of Optics and Optometry claims that the contact lens he designed reverses hyperopia. The technique that he applied is called corneal reshaping, or orthokeratology, and consists in using special gas permeable contact lenses to change the shape of the cornea and thus correct vision defects.

The lenses are to be worn at night, during which they will exert pressure on the tear film coating the outside of the cornea and change the shape of the cornea. In the morning, patients will enjoy perfect vision just like after a LASIK surgery, only temporarily.

The only drawback of the new method of treating hyperopia is that each pair of lenses has to be custom-made to suit each patient, which significantly increases their cost. At the moment, they are sold at €1000 plus €400 for annual replacement lenses.

Numerous research centres around the world are conducting studies to develop contact lenses with integrated electronic circuits. In the future, such lenses might replace many traditional devices that provide us with information about both the world around us and the world inside our bodies. One such project focuses on lenses that monitor the level of blood sugar. The lenses will be equipped with a glucose biosensor and change colour if a significant drop or increase in blood glucose level occurs.

Normally, diabetic patients need to use glucose meters, which require a drop of blood to ascertain the current glucose level. Such painful and inconvenient tests could become a thing of the past if the research carried out by University of Western Ontario Department of Chemical and Biochemical Engineering is successful.

The new contact lenses will have an additional advantage over the traditional glucose meters. Namely, they will monitor blood sugar level constantly, not at specific intervals prescribed by doctors. Since sudden changes in glucose level are not uncommon, this may prevent serious complications that diabetics are in danger of every day, including diabetic coma.

The star of such films as Charlie and the Chocolate Factory or Pirates of the Caribbean: The Curse of the Black Pearl usually prefers wearing glasses, but when it comes to making films, he often uses coloured contact lenses. These frequently give him an eccentric look, making his characters unforgettable. His Mad Hatter in Alice in Wonderland is a case in point.

Bright green contact lenses with a black outline immediately draw the viewer’s attention and effectively emphasise the character’s oddness. The Mad Hatter’s costume is equally colourful, but it is his eyes that immediately become the focus of everybody’s attention. Johnny Depp skilfully uses that, adjusting his acting making the part something to remember.

There is good news for those who would like to look like Johnny Depp in the film. Specially designed Mad Hatter Effect contact lenses are available for purchase. What is more, if the Mad Hatter look does not seem extraordinary enough, it is also possible to buy Cheshire Cat contact lenses, so all fans of Alice in Wonderland should be satisfied.

A recently published study, whose findings were presented at an annual meeting of the Association for Research in Vision and Ophthalmology, suggests that a new type of contact lenses may reduce the progress of myopia. The key aspect is that the lenses fully correct the central vision while simultaneously decreasing the relative peripheral hyperopia.

100 Chinese children aged 7-14 participated in the study and were given the modified contact lenses. After the 6-month period of the study, the participants exhibited 54% lower progression of myopia in comparison with the children from the control group.

Though the results are only preliminary, and researches agree that a long-term study is necessary before drawing final conclusions and starting mass production of the new lenses, the data look promising and we may expect a new generation of contact lenses that will effectively slow down the progress of myopia.

It is still unsure, but there seem to be no contraindications for using the technology in both daily contact lenses and monthly contact lenses.

It may sound counterintuitive, but disposable daily contact lenses seem to have a smaller impact on the environment than weekly or monthly contact lenses. This unexpected conclusion is based on the fact that daily contact lenses do not require, unlike weekly and monthly contact lenses, solutions necessary to keep them clean and ready for use. Previous calculations did not take that into consideration, focusing only on the material and production process of the lens itself.

Moreover, several companies are working on making daily contact lenses even more eco-friendly. Basically, they are developing technologies that would allow them to produce contact lenses from renewable materials.

It is estimated that more than 125 million people worldwide (approximately 40m in the US alone) wear contact lenses, and this number is constantly rising. Bearing that in mind, environmental issues concerning contact lenses – in spite of the product’s deceptively small size – should not be disregarded. To the satisfaction of environment-conscious customers, the multi-billion industry appears to have finally understood that.

A study conducted among 1,654 American users of contact lenses suggests that a significant number of them do not follow the recommended replacement schedules. The resulting complications include various types of eye infections causing conjunctivitis, keratitis and other severe conditions.

The study revealed that:

• 59% of the wearers of silicone hydrogel lenses that should be replaced every two weeks wore them longer
• 29% of the wearers of one-month silicone hydrogel lenses failed to replace them on time
• 15% of those who wear daily contact lenses used them for longer periods

The two main reasons given for this fact are financial problems (some wearers used them longer than they should to save money) and simple forgetfulness (51% of the participants of the study had problems remembering when to buy new lenses). The latter group could make use of the recently launched lens care timer and effortlessly solve the problem.

The most worrying conclusion of the study was the fact that as much as 18% of contact lens wearers considered cleaning them every day merely “somewhat important” or “not important”, which emphasises the need for educating patients more effectively.

It appears that wearing contact lenses may have consequences that go beyond medical ones, especially when it comes to children and teenagers. 484 myopic children aged 8 to 11 took part in a recently published study; half of them wore glasses while the other half wore contact lenses (daily contact lenses and 2-week disposable contact lenses).

After the 3-year period of the study, the children were asked several questions concerning their self-perception (how they perceived their appearance, sports skills, academic skills, social acceptance and general self-esteem).

Compared to the children who wore glasses, children wearing contact lenses reached higher scores regarding appearance, sports skills, academic abilities and social acceptance. They showed more self-confidence in these areas. However, their general self-esteem was the same in both groups.

The authors of the study conclude that, when choosing the method of vision correction for children, ophthalmologists and parents should consider their impact on both the child’s eyesight and psyche. Increased self-confidence might have an enormous positive influence on the child in the crucial years of his or her psychological development.

A report presented at the 239th National Meeting of the American Chemical Society (ACS) in San Francisco states that vitamin E may be helpful in extending the release of drugs used for the treatment of glaucoma.

The disease is usually treated with eye drops that decrease the abnormally high intraocular pressure that gradually damages the optic nerve, which may eventually lead to permanent blindness. However, it is estimated that only 1 to 5% of medicines contained in eye drops reach the cornea of the eye. The new approach, scientists claim, will increase the time of the presence of the drugs in the eye by as much as 100 times.

Here, vitamin E acts as a kind of barrier for drugs, thus extending their release time and enhancing their effectiveness. Scientists are also examining how vitamin E may facilitate the treatment and prevention of other ophthalmic conditions. The technology is to be used in both daily contact lenses and extended wear lenses (up to a month). Clinical trials are to begin in one to two years.