Tag Archives: Contact

Gold-infused contact lenses that treat red-green color blindness could hit the market soon

New research is aiming to bring color back into the lives of the color-blind.

Image credits n4i Photo / Flickr.

Color blindness can manifest itself in several ways, from people seeing certain colors in muted shades to not perceiving some at all. Needless to say, this is not the most enjoyable way to live your life and can cause real issues with color-cues, such as difficulties navigating a traffic light. Some of our fixes so far include tinted glasses or dyed contact lenses, but they all have their own shortcomings. The glasses can’t be used to also correct vision (so some people need to pick one or the other condition to fix), and the lenses can be unstable, potentially harmful if not used properly.

A new paper, however, reports on a new approach that can help address this issue: infusing contact lenses with gold particles.


Color blindness is a genetic disorder so, for now, our best approach to the issue so far is to treat its symptoms. The main issue with contact lenses employed for this purpose is that, although they are effective in improving red-green color perception, clinical trials have shown that they can leech the pigments they’re dyed with, potentially harming users’ eyes.

The current paper describes how the authors used gold nanocomposite materials to produce lenses with the same effect, but no dye. This process has been used for centuries already to produce ‘cranberry’ glass, they explain, and comes down to how the gold scatters light going through the glass.

In order to produce them, the team put together an even mix of gold nanoparticles and a hydrogel polymer. The end result was a rose-tinted gel that filters light within the 520-580 nm range, which corresponds to the colors red and green. Several types of nanoparticles were tested, and those who were around 40 nm in diameter were the most effective. During lab testing, lenses built with nanoparticles of this size did not clump, nor did they over-filter the color.

The lenses have the same water-retention properties like those of commercial lenses, and were non-toxic to cell cultures in the lab.

After comparing their lenses’ efficiency to those of two commercially-available pairs of tinted glasses and the pink-dyed contact lenses. The gold-infused lenses blocked a narrower band of the visible spectrum, and a similar amount to that of the dyed contact lenses. This suggests that the gold nanocomposite lenses would be effective for people with red-green colorblindness, but without the health concerns.

The lenses will now undergo clinical trials to assess their efficiency, safety, comfort, and practicality with human patients in real-life situations. If they pass, we could see them available commercially.

The paper “Gold Nanocomposite Contact Lenses for Color Blindness Management” has been published in the journal ACS Nano.

contact lens.

Contact lenses break down into microplastics — so don’t flush them down!

Just throw them in the trash if you don’t want them on your plate later on.

contact lens.

Contact lenses recovered from treated sewage sludge could harm the environment.
Image credits Charles Rolsky.

Unlike glasses, contact lenses are intended for very short usage periods — most are meant to last a single day. Their disposability may have dire consequences for our oceans, however, according to new research. The paper reports that throwing contact lenses down the drain after use may contribute to microplastic pollution.

The researchers are presenting their results today (Monday 20th August) at the 256th National Meeting & Exposition of the American Chemical Society (ACS) in Boston, Mass.

Break-down lenses

Rolf Halden, Ph.D. and paper lead author, says the work was borne of personal experience.

“I had worn glasses and contact lenses for most of my adult life,” Rolf explains. “But I started to wonder, has anyone done research on what happens to these plastic lenses?”

Rolf’s team — which was already involved in plastic pollution research — couldn’t find a single study detailing what happens to these lenses after use. So they decided to research the topic themselves.

They started with a survey aimed at contact lens wearers in the U.S. It revealed that between 15 to 20% of all users flush the lenses down the sink or toilet after use. Considering that roughly 45 million people in the U.S. alone wear such lenses, that’s a lot of people.

Lenses disposed of in this way end up in wastewater treatment plants — between 6 to 10 metric tons of plastic lenses suffer this fate each year in the U.S. alone, the team estimates. As they tend to be denser than water, these lenses sink. This could ultimately pose a threat to aquatic life, especially bottom feeders that may ingest the contacts.

Direct observation of what happens to these lenses in a wastewater treatment plant was a challenge for several reasons. First off, they’re transparent — making them exceedingly hard to track in wastewater. Secondly, contact lenses are made of a special kind of plastic. Unlike other plastic waste (which is largely composed of polypropylene), contact lenses are usually made from a combination of poly(methylmethacrylate), silicones, and fluoropolymers. This material is much softer and permeable to oxygen. However, its behavior in wastewater and wastewater treatment plants was undocumented.

As part of their research, the team exposed five polymer blends found in the majority of lenses to populations of aerobic and anaerobic microorganisms from wastewater treatment plants. Samples of each polymer were exposed to wastewater for varying lengths of time, and finally performed Raman spectroscopy to analyze the material.

The team concluded that microbes in the wastewater treatment facility actually altered the surface of the contact lenses, weakening the bonds in the plastic polymers.

“We found that there were noticeable changes in the bonds of the contact lenses after long-term treatment with the plant’s microbes,” says coauthor Varun Kelkar.

“When the plastic loses some of its structural strength, it will break down physically. This leads to smaller plastic particles which would ultimately lead to the formation of microplastics.”

Marine animals often mistake microplastics for bits of food. Since plastic isn’t digestible, however, these microplastics have a severe effect on the animals’ digestive systems. Since oceans support complex food chains, microplastics can pass from the small fry to larger fish and eventually end up on your plate (or in your glass). Contact lenses could thus lead to unwanted exposures to plastic contaminants and the pollutants that stick to their surfaces.

This is the first research looking into the effects of contact lenses in wild ecosystems, the team notes. They hope their work will determine industry to at least provide labels on the lenses’ packages describing how to properly dispose of the devices — placing them alongside other solid waste.

“Ultimately, we hope that manufacturers will conduct more research on how the lenses impact aquatic life and how fast the lenses degrade in a marine environment,” Halden confesses.

The findings will be presented at the 256th National Meeting & Exposition of the American Chemical Society. You can watch it live here.

The Search for Alien Life: We Have Been Looking in the Wrong Places

SETI Initiative. Source: Traces Online.

Humanity has pondered the existence of alien life for centuries. However, it has been in just the past 100 years or so that modern science has backed some of this thinking. Scientists of the late 1800’s and early 1900’s believed that objects appearing on the surface of Mars were canals constructed by aliens. Particularly, astronomer Percival Lowell believed this concept and promoted it in works such as the book Mars As the Abode of Life (1908).

This belief in the scientific community led to a huge amount of pop culture based around the concept of extraterrestrials. This has resulted in some people even believing in the existence of aliens like the ones in the movies. Who knows? They could be out there. But some wonder how probable their existence is.

With aliens constantly being depicted in entertainment, even after the Martian alien canal hypothesis was busted, scientists considered communicating with otherworldly life forms. The first scientists looking for a close encounter believed the best bet was to use radio waves as the communication medium. The first of such proposed experiments was conducted in 1960 by astronomer Frank Drake.

One of the most eye-opening quotes about extraterrestrial alien life comes from the book Time for the Stars by Alan Lightman. The author states, “Are we alone in the universe? Few questions are more profound… Extraterrestrial contact would forever change the way we view our place in the cosmos” (Lightman 21).

Drake would definitely not be the last scientist to attempt to summon a response from an alien. But this was the first modern example of tests which would now be referred to as part of SETI, the search for extraterrestrial intelligence. In 1980, to bring more of a public interest to SETI, the legendary astrophysicist, astronomer, and astrobiologist Carl Sagan and several others formed The Planetary Society. In more recent years, other programs with goals similar to SETI’s have been established such as METI, messaging extraterrestrial intelligence.

Apart from radio waves, humans have tried other ways of communicating with hypothetical aliens. One example is a plaque which was attached to the Pioneer 10 probe in 1972. This plaque would be a unique kind of “message in a bottle,” except the ocean it was doomed to drift in was far more vast than any sea on Earth. It was inquired of Carl Sagan about sending such a message several months before the scheduled departure of the craft. So Sagan went to work, and assisting him with this undertaking was none other than Frank Drake, the man who had conducted the first modern SETI tests in 1960. The fruit of numerous labors and laborers, the Pioneer 10 plaque that was sent into space depicted a man and a woman and several objects. Through the imagery, the scientists were trying to give any aliens who might see this plaque an idea of what humans are like and where Earth is located.

This could be the first big mistaken researchers are making. They are looking to make contact. They are putting their faith in a sci-fi movie concept. What these scientists are attempting to do is call up and have a conversation with an alien or, better yet, a race of aliens. This is not to say that SETI is pointless, but it might not be the most opportune method for seeking alien life.

Perhaps scientists should strive to discover life in its simpler forms. As Lee Billings of Scientific American states in a recent article, if you were able to travel to another planet it is likely “you would find a planet dominated by microbes rather than charismatic megafauna.” Many scientists are now suggesting microscopic organisms could be more plentiful throughout the cosmos than macroscopic creatures.

Microbes Are a Realistic Form of Alien Life. Source: Joi Ito’s PubPub.

A specific search for such minuscule life forms is not a new practice. Bacteria are, of course, microbes. Astrobiologists like Richard Hoover and Dave McKay have examined certain meteorites. Some of the microscopic structures found embedded in or on the space relics resemble bacteria. They have released their findings in past years. They have admitted that even though the fossilized structures appear to be remnants of bacteria there is still some skepticism as to whether those structures are alien in origin. This is because bacteria from Earth could have been attached to the meteorites once they entered our atmosphere.

So how do scientists narrow down the search for alien life even further? Billings’ piece may give us the best idea available at the moment. He informs his readers that one of oxygen’s properties is that it tends to descend from an atmosphere in the form of mineral oxides. It does not remain in its gaseous phase for long. Because of its nature, in an atmosphere such as Earth’s, the oxygen has to be reinstituted on a regular basis.

Astrobiologists have to accept oxygen may be one of the least familiar elements they come upon when studying potential life-supporting bodies. For example, atmospheric chemist David Catling has said the atmosphere of a world dominated by microscopic life could be largely comprised of methane and carbon dioxide gases. Keeping this in mind, this will hopefully narrow down the most likely planet candidates for life.

You can’t keep eye contact during conversation because your brain can’t handle it, study finds

A new study suggests that we may struggle to maintain eye contact while having a conversation with someone because out brains just can’t handle doing both at the same time.

Image credits Madeinitaly / Pixabay.

It’s not (just) shyness, it seems. Scientists from Kyoto University, Japan tested 26 volunteers on their ability to play word association games while keeping eye contact with computer-generated faces. Their results suggest that people just can’t handle thinking of the right words while keeping their attention on an interlocutor’s face. The effect, they found, becomes more noticeable when the participants had to think up less familiar words — implying that this process uses the same mental resources as maintaining eye contact.

“Although eye contact and verbal processing appear independent, people frequently avert their eyes from interlocutors during conversation,” write the researchers.

“This suggests that there is interference between these processes.”

The participants were asked to think of word associations for terms with various difficulty levels. Thinking of a verb for ‘spoon’, for example, is pretty easy — you can eat with it. Thinking of a verb associated with the word ‘paper’ is harder since you can write, fold, cut it, and so on. Participants were tested on their ability to associate while looking at animations of faces maintaining eye contact and animations of faces looking away.  And in the first case, they fared worse.

It took them longer to think of answers when maintaining eye contact, but only when they had to associate a more difficult word. The researchers believe that this happens because the brain uses the same resources for both actions — so in a way, talking while maintaining eye contact overloads it.

The team suspects that participants may be experiencing some kind of neural adaptation, a process in which the brain alters its response to a constant stimulus — take for example the way you don’t feel your wallet in the back-pocket you usually put it in but becomes uncomfortable in the other one. The sample size this team worked with is pretty small, so further research is needed to prove or disprove the findings.

The paper “When we cannot speak: Eye contact disrupts resources available to cognitive control processes during verb generation” has been published in the journal Cognition.