Thursday, February 8, 2018

Contact Lenses: More Than Meets The Eye

Contact lenses probably seem like a pretty recent invention, right?

It’s true that they’ve only become popular in recent decades, but you might be surprised to learn that Leonardo da Vinci first sketched the concept of contact lenses way back in 1508! His version involved submerging one’s head in a glass bowl of water, so it definitely needed work, but how did we get from there to the breathable silicone hydrogel contact lenses of today?

Contact Spectacles: Contacts Made Of Glass

In 1827, over three centuries after da Vinci’s initial sketch, Sir John Herschel came up with the idea of making a mold of a person’s cornea (the outer portion of the eye) in order to correct vision. However, the technology for making glass lenses thin enough to fit in the eye wouldn’t come along until 1888, when Adolf Fick was finally able to construct the first contact lens.
So why aren’t there fewer pairs of spectacles in old black-and-white photos if contacts were invented in the 1880s? Well, these prototype contact lenses weren’t exactly comfortable. They covered the entire front of the eye and allowed no oxygen to reach the cornea, so it only took a few hours before they became too painful to wear.

Hard Lenses: The Plastic Revolution

Contact lenses might never have become practical enough to appeal to glasses-wearers if it hadn’t been for the invention of plastic, which allowed lenses to be made lighter and more durable. Another key component was being able to successfully make molds of patients’ eyes, as Herschel had theorized. Dr. Dallos and Istvan Komàromy of Hungary perfected a method of doing just that.
However, these lenses still covered the entire eye. It wasn’t until 1948, when an English optical technician discovered that the lenses still worked if they covered a much smaller surface area, that contacts began to resemble the corneal lenses we’re used to today. A few more improvements quickly followed, making hard lenses very thin, shaped to the eye, and more comfortable.

Soft Lenses: Sight For Sore Eyes

Over the next couple of decades, hydrogels (more flexible plastics) were developed. By 1971, the first soft contact lenses gained FDA approval and hit the market. Hard lenses couldn’t beat soft lenses for comfort. Infection is always a risk with lenses that touch the eye, but the introduction of disposable lenses reduced this risk as well.
Soft lens technology has improved in the nearly fifty years since 1971, always seeking to improve breathability, safety, and comfort levels. The biggest recent breakthrough was silicone hydrogels, which are almost 100 percent breathable.
Watch this video to see how contact lenses are made:

Let’s Find Your Perfect Contacts!

With the variety of contact lens options available today, it might seem difficult to choose the right ones for you, but that’s where your local Vision Source® member optometrist comes in. They can match you with the perfect lenses for your circumstances and needs, so if they haven’t seen you in a while, schedule an appointment right away!

Tuesday, January 16, 2018

Presbyopia And Progressive Lenses

Presbyopia is caused by reduced elasticity of the eye’s lens, affects nearly everyone older than 65.

About 42 percent of Americans who are in their prime are nearsighted. For them, a simple pair of reading glasses can’t solve the problem of presbyopia, and that’s where bifocals, trifocals, and progressive lenses come in.

Options For Correcting Presbyopia

Bifocals are simply glasses with lenses that have one area that corrects nearsightedness and a smaller area in the lower half that corrects farsightedness. As presbyopia worsens, middle distances can also become difficult to focus on. This can be corrected by trifocals, which add a strip in between the two prescriptions in bifocals, allowing wearers to see things like their computer screens better.
The trouble with bifocals and especially trifocals is that the lines between the different sections of the lens are difficult for the wearer to ignore, causing a jarring “image jump” effect, and they also serve as a giveaway to other people that they’re getting older. Fortunately, people who are nearsighted and dealing with presbyopia have another option that doesn’t have these drawbacks, and that’s progressive lenses.

How Progressive Lenses Work

So how do progressive lenses do the same job as bifocals or trifocals without those pesky lines? Unlike bifocals and trifocals, which are multiple lenses combined into one, a progressive lens is a single lens. The prescription gradually changes along a corridor of power from distance vision at the top to middle vision in the center to near vision at the bottom. This allows wearers to see at all distances, depending on how they tilt their heads.
There is a tradeoff to make this complex lens design possible, which is that anything seen through the bottom corners of a progressive lens will look blurred. However, newer designs and technology are helping to reduce this flaw. In addition, when optometrists examine patients for these lenses, they take measurements of the eyes and frames so they can put that corridor of power in the exact location it needs to be so patients can see normally.

Tips On Adjusting To Progressive Lenses

Like any new prescription, progressive lenses require an adjustment period. If you’re thinking about trading in those trifocals for some sleek progressive lenses, or if you’re new to progressive lenses and struggling to adjust, here are some tips to make the process easier.
  • Make sure your glasses are properly fitted so that they stay high on your nose where you can get the most out of them.
  • Move your head to see different things, not your eyes, and point your nose at what you want to focus on.
  • Practice focusing on different distances by reading a magazine while watching TV.
  • Stick with them! Switching back and forth to your old glasses will make adjusting much more difficult, so resist the temptation!

Come In To See Your Optometrist

Don’t hesitate to come to your local Vision Source® member optometrist with any questions you have about progressive lenses. They’ll be happy to prescribe you the perfect lenses as well as help you find the perfect frames, and they can’t wait to see you!

Thank you for trusting Vision Source®!