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 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 Kom├áromy 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 one of our optometrists come 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

Thursday, January 4, 2018

Glaucoma: The Basics

The optic nerve is what transmits visual data from the eye to the brain.

When the optic nerve is damaged, our vision suffers. A group of conditions that threaten the optic nerve is glaucoma. In the Canada, glaucoma is the second most common cause of vision loss and blindness, affecting three million people. Because January is National Glaucoma Awareness Month, we wanted to give our patients a basic understanding of the condition.

The Internal Pressure Of the Eye

Normally, aqueous humor (the fluid in the front chambers of the eye) is able to drain away at the same rate it is produced, keeping everything balanced. Glaucoma occurs when the drainage canals become blocked. Pressure begins to build, which eventually pushes the lens back. This, in turn, causes the vitreous humor (the fluid in the larger rear chamber of the eye) to press against the blood vessels and optic nerve, damaging them.

The Different Types Of Glaucoma

The two most common types of glaucoma are open-angle glaucoma and angle-closure glaucoma. At least 90 percent of all glaucoma cases are open-angle. Rarer types of glaucoma include congenital (from birth) and traumatic (caused by injury), and there are several others.
Open-angle glaucoma develops very gradually, as the drainage canals of the eye become clogged and the fluid isn’t able to drain effectively. What makes open-angle glaucoma so nefarious is that it rarely has noticeable symptoms. The peripheral vision gradually goes dark, but the central vision remains sharp, so it may seem like nothing is wrong until the condition has advanced. This is why regular comprehensive eye exams are essential, particularly after age 60 (or earlier if there is family history of glaucoma).
Angle-closure glaucoma occurs when the iris itself blocks those drainage canals, causing a much more sudden rise in pressure and obvious symptoms, such as headaches, eye pain, nausea, rainbows around lights at night, and very blurred vision. If you experience these symptoms, come see us immediately. We can also check if your angle is wide or narrow to determine whether you’re at risk of developing angle-closure glaucoma.

Stopping Glaucoma In Its Tracks

The lack of early symptoms in the vast majority of glaucoma cases might seem scary. The good news is that as long as you come in for your regular eye exams, we can detect glaucoma much earlier than you can, and then we can treat it. Before age 60, it’s usually enough to have one eye exam every two years, but people over 60 should schedule them once a year. Your individual risk factors may require more frequent exams.

Help us help you keep your eyes healthy for life!

For more information or to book an appointment, visit us at www.hollyburneyeclinic.com.
Top image used under CC0 Public Domain license. Image cropped and modified from original.
source

Wednesday, October 18, 2017

Optometry Giving Sight Leads Global Coalition to Support World Sight Day Challenge

11th year of the Challenge!

Our team at Hollyburn Eye Clinic is thrilled to participating in the World Sight Day Challenge again this year. We are fundraising throughout October and have some amazing draw prizes with all proceeds being donated to Optometry Giving Sight.

Global eye health and vision care are more important than ever in light of recent natural disasters including major hurricanes, earthquakes, tsunamis and their aftermath. As people deal with these and other health crises, leading North American optometric companies, networks, schools and practices are once again joining a coalition led by Optometry Giving Sight in support of World Sight Day (October 12, 2017) and the World Sight Day Challenge, which runs through October.

This is the 11th year of the Challenge, which encourages all members of the vision care community to make a donation or participate in a fundraising event to help fund sustainable eye health projects for people who are needlessly blind or vision impaired. These include support for projects that will help give sight and hope to more than 1 million children as part of the Our Children’s Vision campaign - and this year, in recognition of recent events, projects providing eye care to people affected by the hurricanes in our region.

“If everyone does just one thing in support of the Challenge we can make a huge difference in the lives of millions.”

Wednesday, September 20, 2017

Eye Health & Exam Frequency – School-age children

School-age child’s eyes are constantly in use in the classroom and at play. For school-age children, several different visual skills must work together so they can see and understand clearly. If any of these visual skills are lacking or impaired, your child will need to work harder and may develop headaches or fatigue. Often the increased visual demands of schoolwork can make greater demands on a child’s visual skills, pointing out a vision problem that was not apparent before school. The child may not realize they have a vision problem, they may simply assume everyone sees the way they do.
A vision-related problem may cause some or none of these symptoms:
  • headaches or irritability
  • avoidance of near or distance work
  • covering or rubbing of the eyes
  • tilting of the head or unusual posture
  • using a finger to maintain place while reading
  • losing place while reading
  • omitting or confusing words when reading
  • performing below their potential
  • holding objects close to their face
  • sitting close to the television
  • short attention span for age
Conditions that may emerge during this stage in your child’s life include myopia or nearsightedness(blurred vision when seeing objects at a distance), hyperopia or farsightedness (blurred vision when seeing objects up close) and astigmatism (distorted vision at all distances).
If your child has had a sight or vision screening at school, know that not all eye tests are created equal, and that this should not replace a comprehensive eye exam. Tests or screenings done at school cannot be used to diagnose an eye-health or learning related vision problems. Studies show that vision screening tests have high error rates; with many children with vision problems being able to pass a vision screening test.
Protect your child’s vision by booking a comprehensive eye exam with a doctor of optometry. Your child should have a complete optometric eye exam at six months, before starting kindergarten, and annually throughout the school years to ensure optimal eye health and developmental progress, or if you notice any of the symptoms listed above appearing between appointments.
During a comprehensive eye exam, your child’s optometrist will perform a series of tests that will determine the quality of their vision and overall health of the eye. These tests may include:
  • Slit lamp: This is a high-powered microscope that allows the optometrist to look deep inside your child’s eyes, ensuring the cornea, iris, lens and blood vessels in each eye appear normal and healthy.
  • Manual refraction using a phoropter: A phoropter is a machine that allows your child to view objects through a variety of lenses to see what combination is the clearest. It helps determine if your child requires a prescription for glasses or not.
  • Stereopsis: Various tests are used to see whether your child’s eyes are working together, one of those tests uses 3D glasses.
  • Visual acuity: Using eye charts made up of letters, symbols, tumbling E or pictures, your optometrist will ask what your child can see. This helps the doctor determine how clear your child’s vision is.
  • Colour-blind test: Using a variety of patterns and colours, your optometrist will ask your child to identify the objects or numbers hidden within. If your child is colour blind, the patterns will appear different than they would for a person with normal colour vision.
  • Retinoscopy: Your optometrist will use a target and ask your child to focus on that target while the optometrist shines a light in their eye. The optometrist will flip through a variety of lenses. This test helps determine the lens prescription.
  • Binocular Vision Testing: This includes a number of tests including a ‘cover test’ and checking that all of the extra-ocular muscles are functioning properly.
In addition to scheduling your children for regular comprehensive eye exams, your doctor of optometry is available to discuss various topics. Many are available for urgent care appointments (pink eye, eye injuries, etc.), they can help treat allergies, and can discuss eyewear solutions with you.

Friday, September 15, 2017

More kids show eye strain from digital devices, optometrist warns parents

A Calgary optometrist says she's seeing more cases of digital eye strain among kids and, as they head back to school, now is the best time to get that problem sorted out.

"We're seeing it more for them than we have in the past," said Andrea Lasby.

"So where it used to be primarily a millennial — 20-, 30-, 40-year-old problem — we're kind of seeing it intergenerational at this point, including children."

The root cause could be parents who don't understand the effects on children.

Not taking breaks

An online survey commissioned by the Alberta Association of Optometrists (AAO) revealed that 59 per cent of parents in the province "are not aware of or do not encourage their children to take steps during or after using digital devices to reduce the impact on their eyes."

"Digital eye strain is the discomfort experienced after screen use for more than two hours at a time," Dr. Jim Asuchak, practicing optometrist and president of the AAO, said in a news release on the study.

"Alberta children are, on average, spending at least double that amount of time on digital devices, and we are seeing the results in our exam chairs."

Kavan Shergill, 8, sitting for an exam with Lasby, said his eyes have been dry and itchy lately and that he gets headaches, especially after spending time on his iPad.

"I'm trying to not go on it, but like, I can't," he said. "It's hard." 

Eye irritation and blurriness can impair learning

According to Lasby, Shergill's symptoms are all early signs of digital eye strain.

She says the long-term impacts are not yet known because it's such a new phenomenon, but the irritation and blurriness can impact learning in the classroom.

"Children oftentimes don't know what they're feeling is inappropriate or that it's not normal, so they don't complain. They just think blurriness, that's normal," said Lasby.

"Or perhaps they say 'I'm reading, it's blurry, I don't feel like doing this anymore,' and now they're hyperactive and they move around a lot, so sometimes that hyperactivity is a misdiagnosis and it can be an eye problem."

How to avoid eye strain

Parents can also encourage children to take preventative measures at home and at school to reduce the risk of digital eye strain, including:
  • Take regular breaks.
  • Follow the 20-20-20 rule by looking 20 feet away every 20 minutes for 20 seconds.
  • Don't hold screens too close, especially for long periods of time.
  • Eliminate screen glare by reducing overhead lighting.
  • Position computers slightly below eye level and at arm's length.
  • Increase text size on digital devices.
  • Adjust screen brightness.
Teens spend almost 8 hours daily on digital devices

According to the AAO survey, Alberta parents said elementary school-age children spend more than four hours each day using digital devices at home and at school. For teenagers, that number increases to nearly eight hours each day.

Lasby says symptoms can be treated with eye drops, special eye glasses and blinking exercises. She said there are also apps that can adjust the colour temperature of screens to reduce the impact.

The AAO's survey was conducted online through the polling firm Angus Reid from July 13 to July 18 among 506 Albertans with children under the age of 18.

For comparison purposes only, a random sample of this size would yield a margin of error of plus or minus 4.4 percentage points, 19 times out of 20.

If you have any questions, concerns, or would like to book an appointment, please visit us at www.hollyburneyeclinic.com.

Tuesday, September 5, 2017

Myopia Connected to Sleep Hormone

An Ulster University study has found higher levels of the sleep-regulating hormone, melatonin, in individuals with myopia than in those who are not short-sighted.

Scientists assessed melatonin levels in a group of 54 young adults over an 18-month period before publishing their findings in Ophthalmic and Physiological Optics.

Melatonin levels were measured between 8.30am and 10am in the morning, with study participants fasting from 10pm the previous evening.

Researchers discovered that those with myopia had three times the levels of melatonin than those without the condition.

The long-term aim of the research is to determine whether sleep patterns are linked to short-sightedness, and to explore whether sleep pattern management could be used as a low-cost way of managing myopia.

Ulster University lead researcher, Professor Kathryn Saunders, emphasised that while having a myopic parent plays a role in whether a child is short-sighted, the rate at which children are becoming myopic suggests that there are more factors involved than genetics alone.

“Our modern lifestyles are also having a significant impact. Even mildly short-sighted eyes are at future risk of a number of serious, sight-threatening conditions such as glaucoma, retinal detachment, macular degeneration and cataracts,” she emphasised.

“Our research suggests that the body clocks’ of the short-sighted adults in our study were different, which is exciting because if these differences are also found in children, they may help us better understand which aspects of modern lifestyles are causing more children to become short-sighted than ever before,” Professor Saunders outlined.

Previous Ulster University studies have shown that children who spend less time outdoors are at an increased risk of becoming myopic and highlighted that there are now twice as many post-primary school-aged children in the UK diagnosed as short-sighted than there were 60 years ago.

If you have any questions or concerns about your eye health, please contact us at www.hollyburneyeclinic.com.