Research & Publications

What Is Refractive Error?

Vision is a pretty amazing thing – except for when it isn’t. Over 75 per cent of Americans are estimated to wear optical correction in the form of spectacles or contact lenses. And it’s thought that even more should be wearing some form of optical correction but instead wear some form of denial to address refractive error.

Refractive error occurs when the eye cannot properly focus which, of course, results in blurred vision. The 4 most common types of refractive error are myopia, presbyopia, hyperopia, and astigmatism.
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Color Perception, Photoreceptors and the Different Types of Colorblindness

Contrary to what the name suggests, colorblindness isn’t an absolute blindness to color. The perception of color is a complex process involving the eyes and the brain, and even two people who consider themselves “color vision normal” may disagree on certain hues – is that sunset more pink or purple? In a person with a diagnosed color vision deficiency (a more accurate term), they usually will experience what is considered a “shortened spectrum”, meaning they are able to distinguish fewer colors compared to a color-normal person and may confuse a few different shades as the same color. In Caucasian populations, the overall prevalence of colorblindness is typically quoted as 8% in males and 0.5% in females. A study conducted in Californian preschool boys found the lowest rate of colorblindness in African American at 1.4% and the second lowest in Hispanic boys at 2.6%.

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All About Pink Eye (Conjunctivitis)

Most people at some point in their lives will experience an unpleasant but usually mild condition known as pink eye, or conjunctivitis. It typically starts as a burning, gritty, or itchy sensation, accompanied by some sort of unsightly discharge, and – as you would expect – the whites of the eye turn pink. An estimated 6 million Americans are affected by conjunctivitis every year with the annual cost of treating bacterial conjunctivitis predicted to be as high as $857 million.
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Idiopathic Intracranial Hypertension (IIH)

Idiopathic intracranial hypertension (IIH) is an uncommon condition involving an increase in intracranial pressure in the brain of unknown cause. It goes by a couple of other aliases, including pseudotumor cerebri, due to the signs and symptoms mimicking a brain tumor (“pseudotumor” means “false brain tumor”), and benign intracranial hypertension. It is estimated that about 100,000 Americans suffer from IIH.
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How Eyes Offer Clues About the Health of Your Body

The full list of systemic diseases associated with signs in the eye is one that is too long to be contained in a single post. It ranges from the obscure syndromes such as Marfan’s and Vogt-Koyanagi-Harada (that would be a mouthful to say) to the more well-known conditions of diabetes and hypertension. Don’t forget, the same blood that runs through your liver and down through the blood vessels of your toes eventually also circulates through your eyeballs.

The role of an eyecare practitioner is sometimes akin to that of a detective – picking up various little clues during an eye examination that could result in making a deduction about your cholesterol levels or the presence of a certain gene in your DNA, perhaps even making a link to your ongoing bowel problems or mouth ulcers.
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All About Retinitis Pigmentosa

Reti-whatty pigmen-who? Retinitis pigmentosa (RP), almost as complicated to spell as Gnadenhutten, Ohio and as awkward to say as Coxsackie, New York, is an inherited disease of the retina that often results in blindness. The prevalence of this disease sits around 1 in 4000 and though much research is being devoted to a cure or at least a treatment, currently nothing has been found to fully restore sight in RP sufferers.

The vision loss experienced in Retinitis Pigmentosa develops due to a mutation in any one of over 50 genes, which causes the photoreceptors of the retina to slowly die. The retina is the sensory layer of tissue inside the eyeball and is comprised of a number of layers in itself, one of which is a layer of light-sensitive cells known as photoreceptors that detect light entering the eye before sending the signal down a pathway which eventually ends in the brain for interpretation into what we know as “vision.” Two types of photoreceptors exist – rods and cones, named as such because they resemble – wait for it – rods and cones! In simplified terms, rods predominantly populate the periphery of the retina and thus deal with peripheral vision, while cones are found in their highest density at the central retina in the area known as the macula and are responsible for fine detailed central vision. Other differences between rod and cone photoreceptors include the fact that rods function better in dim lighting while vision in bright light relies on cones; cones are able to detect color while rods are more or less color blind.

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The Myopia Epidemic

The phrase “short-sighted” can be used in a variety of different contexts. For example, “Purchasing that bright purple couch before seeing the finished house was a rather short-sighted decision”, or “My grandpa is so short-sighted that I can stand a foot away and he’ll think I’m my sister. But I’m actually John.”

Myopia, the medical term for short-sightedness, is a type of refractive error of the eye that involves the focusing point of the eye falling in front of the retina, meaning a blurry image ends up hitting the actual retina. In other words, the length of the eyeball is too long for the focusing power of the eye. Myopia is typically addressed using minus powered spectacle or contact lens, which alters the path of light entering the eye such that it focuses properly onto the retina to form a clear image to the brain. Without optical correction, a myopic person would have difficulty with seeing distant objects clearly; the amount of blur in the distance would correspond to his/her degree of myopia.
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How Nutrition and Lifestyle Can Significantly Improve Eye Health

It may surprise you to know that your eyeballs are connected to the rest of your body. Now that you know, it shouldn’t surprise you to know that how one takes care of his or her body has the potential to affect the eyes and vision. Good nutrition and a healthy lifestyle are beneficial for every part of the body, but in what ways can we use our knowledge of nutrition and lifestyle to improve eye health?

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What Is Dry Eye Disease?

Dry eye disease may not sound particularly intimidating but those who have experienced severe dry eye know that it can significantly impact quality of life. Think of stubbing your pinky toe – it doesn’t sound like much and pre-stub it’s all good until you jam it into the table leg, then you realize that it’s actually really painful.

A cross-sectional study conducted in 2017 found that over 16 million Americans are projected to have dry eye disease. That’s 16 million Americans living with discomfort of the eyes and compromised vision. The prevalence of dry eye increases with age and is more common in women than men.

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What You Need to Know About Lazy Eye (Amblyopia)

Amblyopia refers to poor vision in one or both eyes due to underdeveloped neural connections between the eyeball and the visual areas of the brain. Also known as lazy eye, in the US amblyopia is thought to have a prevalence of just under 2%. No statistically significant differences have been found between amblyopia in females versus males, or across different ethnicities.

While 2% doesn’t quite count as a wildfire epidemic, if left untreated amblyopia in children can have considerable consequences – difficulties with learning at school, limitations with job options as an adult, and even legal blindness. It also means the person no longer has a so-called spare tire if injury or disease befalls the remaining good eye.

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Research & Publications

Factors that Affect Your Risk of Getting a Pterygium

  Risks are a necessary part of life. Stepping out of the house is a risk – you could get stung by a bee in the garden; …

Can Kids Get Pterygia?

  Pterygium – a benign wing-shaped overgrowth of tissue from the whites of the eye over the transparent cornea. It’s …

The Link Between Pterygia and Melanoma

  Who doesn’t love the sun and surf? The answer is probably nobody. And who loves surfer’s eye? The answer is also …