vision

New spiral lens delivers sharp vision at all distances and lighting

Posted by

0


The lens, with a spiral configuration, excels in diverse lighting and maintains multifocality regardless of pupil size, unlike current multifocal lens.

New lens with spiral surface maintains clear focus across distances in changing light.

New lens with spiral surface maintains clear focus across distances in changing light.

Get a daily digest of the latest news in tech, science, and technology, delivered right to your mailbox. Subscribe now.

A significant advancement in lens technology has been achieved by developing a spiral-shaped lens capable of maintaining clear focus across different distances and under varying light conditions. 

Unlike conventional progressive lenses, which often suffer from distortions, this innovative lens, called the spiral diopter, functions flawlessly, similar to how progressive lenses correct vision, according to researchers at Photonics, Numerical and Nanosciences Laboratory (LP2N).

Its distinctive spiraling design creates numerous focal points, akin to combining multiple lenses. This unique arrangement enables clear vision at different distances.

The team claims its potential applications span various fields, including enhancing contact lens technologies, improving intraocular implants for cataracts, and advancing miniaturized imaging systems.

Eye Twitching: 4 Reasons Your Eye Has No Chill

Posted by

1


No, sir, I am not winking at you.
Vector eye twitching on yellow background

It’s a feeling so subtle, yet so annoying. You’re minding your own business when suddenly your eye starts twitching. While you probably just write it off as one of those things, there are actually a few reasons why eye twitching can crop up—and it doesn’t just happen to you.

“This is very common,” Mark Blecher, M.D., eye surgeon and codirector of Wills Eye Hospital Primary Eye Care, tells SELF. When it feels like your eye is twitching, it’s actually your eyelid muscle (known as the orbicularis oculi) that’s spasming, Dr. Blecher explains. “It can happen several times in a row and then stops, and for some people it can happen again later on that same day,” he says.

There’s actually a technical term for this—myokymia—and it happens due to misfiring of neurons in your eyelid muscle, JP Maszczak, O.D., assistant professor of clinical optometry at the Ohio State University College of Optometry, tells SELF. “This is typically a benign condition around one eye that most people will deal with on at least a few occasions throughout their lifetime,” he says.

Of course, eye twitching can strike at the worst moments and it’s probably not the look you’re going for on a regular basis. So then it’s understandable that you’d want to try to keep future eyelid spasms at bay. Here are the most common reasons for eye twitching, plus what you can do to lower your risk of developing it again.

1. You have an eyelid infection.

Eyelid inflammation, which often happens due to a condition called blepharitis, is a big cause of eye twitching, says Dr. Blecher. Blepharitis often happens when bacteria gets into your eyelids, causing inflammation and redness, which makes your muscles twitchy, he explains. If you’re suffering from blepharitis, he recommends taking a washcloth, wetting it with hot water, and holding it over your eye for a few minutes a few times a day. “That can go a long way toward making things better and stopping the twitching,” Dr. Blecher says.

2. You’re stressed out.

You’re up against a crazy work deadline and suddenly your eyelid starts acting weird. While super annoying, this is also totally normal. Stress causes a release of adrenergic chemicals like cortisol and adrenaline, triggering your body’s fight or flight response, John Hovanesian, M.D., an eye surgeon at Harvard Eye Associatesin Laguna Hills, California, tells SELF. “These can cause muscles to be more sensitive and irritable than usual,” he says. Unfortunately, any sort of stress, whether it’s chronic or sudden can cause your eyelid to spasm, says Dr. Blecher

3. You had too much caffeine or chocolate.

The caffeine in coffee and chocolate can cause hyperactivity of the nerves and muscles around the eyelid, leading to eyelid twitching. “I definitely see more benign eyelid twitching right after Valentine’s Day because someone ate too much chocolate,” says Amy Zimmerman, M.D., an ophthalmologist with Katzen Eye Group. Luckily, Dr. Zimmerman says the random twitching should go away once you cut back on your caffeine intake. Anything that stimulates your nervous system will predispose you to eye twitching, Dr. Blecher says, but it doesn’t happen in everyone. So if you know that you’re prone to getting a twitchy eye after you have too much caffeine, it’s best to watch how much you have in the future.

4. You’re super tired.

When you’re wiped out, your sympathetic nervous system, which controls a lot of your involuntary activities, kicks into high gear. And, as a result, your eyelid might start twitching. “For some reason it gets worse the more fatigued you are,” Dr. Zimmerman says. The easiest way to resolve it is by getting more sleep, she says, which may be easier said than done.

Most cases of eyelid twitching don’t need to be evaluated by a doctor, Dr. Maszczak says. But, if the spasming worsens and includes one side of your face or cause your eyelids to close involuntarily, you should call your eye doctor, he says—it could be a sign of a corneal abrasion, dry eyes, or a neurological condition. Most of the time, eye twitching will stop within one to two weeks, but if it’s severe and unrelenting, Botox injections may be helpful, Dr. Maszczak says.

If you experience random eyelid twitching, take a beat and think about what could be causing it. It could be your body’s way of telling you it’s time to de-stress, cut back on the caffeine, or call it an early night tonight—or all three.

A New Theory on the Mysterious Condition Causing Astronauts to Lose Their Vision

Posted by

0


But new research presented this week provides a partial answer to what’s causing this condition: pressurized spinal fluid. Noam Alperin, a researcher at the University of Miami’s Evelyn F. McKnight Brain Institute, presented findings from research he and his peers conducted on 16 astronauts, measuring the volume of cerebrospinal fluid (CSF) in their heads before and after spaceflight. CSF floats around the brain and spine, cushioning it and protecting your brain as you move, such as when you stand up after lying down.

Alperin and his team found that astronauts who had been in space for extended trips (about six months) had much higher build up of CSF in the socket around the eye than astronauts who had only gone on short stints (about two weeks). They also designed a new imaging technique to measure exactly how “flat” the astronauts eyeballs had become after extended periods in space.

The idea is that, without the assistance of gravity, the fluid isn’t pulled down and evenly distributed, allowing it to pool in the eye cavity and build up pressure, which slowly starts to warp the eye and cause the vision damage, called visual impairment intracranial pressure syndrome (VIIP). It’s likely some people are more predisposed to this than others, perhaps due to the shape of their skulls, which would explain why some astronauts have not experienced VIIP. But Alperin said his findings suggest anybody could get VIIP if they’re in space for a long enough period of time.

“We saw structural changes in the eye globe only in the long-duration group,” Alperin told me over the phone. “And these changes were associated with increased volumes of the CSF. Our conclusion was that the CSF was playing a major role in the formation of the problem.”

The results have not been published in a peer-reviewed journal, but Alperin told me the manuscript was recently accepted and will be published shortly. And these reported findings align with what scientists already suspected about the condition, according to Scott M. Smith, the manager of NASA’s Nutritional Biochemistry Laboratory at the Johnson Space Center, who’s been studying the vision loss issue for the last six years.

“I think this fits very well within what others seem to be thinking at the moment,” Smith told me.

Many astronauts—though, importantly, not all—have experienced this unexplained reduction in eyesight after spending months on the International Space Station, some dropping from perfect 20/20 vision to 20/100 in just six months. Researchers have been gravely concerned about this effect. With plans to send humans to Mars by the 2030s, a mission that would require nine months of space flight one way, we don’t really want to risk all of our astronauts going blind in the process.

“NASA ranks human health risks and the two top risks are radiation and vision issues,” Smith said. “Is it number one or two? Some people would say it’s number one, because we don’t really know what the long-term implications are.”

But the better we understand how VIIP occurs, the more likely we are to be able to create a solution. Smith’s team is currently conducting a clinical trial to investigate whether polycystic ovarian syndrome—which, despite its name, may indeed occur in men—could have similar effects on vision. This research could help explain who is more likely to experience VIIP, as research like Alperin’s explores the physical functions of the condition.

What a solution to the condition will look like depends what else we learn: it could be a medication, or a mechanical device to help redistribute fluid, or something else entirely. But each piece to the puzzle helps us get one step closer to sending humans to Mars, and not blinding them in the process.