Nearsightedness...myopia...farsightedness...hyperopia...astigmatism - sometimes it’s easy to mix up the most common results of eye examinations for children, especially after you get home.
Nearsightedness is also known as myopia. In the most simplistic sense, it means it is harder to see further away than it is up close. In the more technical sense, it means that images that enter the eye focus in front of the retina - the sensory back layer of the eye - instead of right on it. This occurs either because the eyeball itself is too long, or the cornea (the front of the eye) is too curved.
While most of the development of myopia is physiologic and unknown, children are more likely be nearsighted if one or both of their parents are nearsighted; as well, in this digital age, there is more evidence showing that longer times at intensive near work like computer use, increase the risk of nearsightedness as well.
The way glasses - or contact lenses - help in seeing clearly, is moving the focus of images from in front of the retina, onto the retina itself.
Farsightedness is also known as hyperopia. Very simply, closer images are harder to focus on than objects at a distance, but it very much can affect both. Technically in this case, images focus behind the retina rather than on it.
The best way of thinking of farsightedness is the eyes being too ‘weak’. Often, children focus (‘accommodate’) to compensate for the weakness, which can strain the visual system if in too high an amount, and past a certain level it can’t be overcome. This is one of the reasons comprehensive examinations are so important, because often far sighted children will have ‘perfect’ vision just from reading a chart.
In the exact opposite of nearsightedness, glasses help in this case by moving the focus forward onto the back of the eye.
Astigmatism is always the most confusing one to understand. It is not a disease of the eye, but like myopia and hyperopia is another type of ‘refractive error’ of the eye. In astigmatism, the front of the eye, or the lens of the eye, has a different curvature - often likened to a football. People who have simple nearsightedness, farsightedness, or no refractive error at all, have one point that the images enter the eye focus at. In astigmatism, there is now two, because of that football shape - the two different curvatures.
In terms of what a child sees, things are distorted far and near, more in one orientation than another.
Glasses and contacts help in this case by moving both of those focusing points onto the back of the eye, the lenses themselves having different curvatures just as the eye does.
While there are many other issues with children’s vision that can be discovered by one of our optometrists at the Eye Gallery during a comprehensive eye examination - from binocular vision issues to health issues - the need for glasses to correct these “refractive errors” is the most common. Be sure to ask any questions to help understand your child’s visual needs!
Did you know that the Canadian Association of Optometrists recommends that children have their first eye exam between 6-9 months of age? While most people assume waiting until school age years is the standard, it is actually a much better idea to get children checked much sooner. Many problems require early intervention, and some can actually stop vision from developing properly if not caught early enough. While a pediatric eye exam doesn’t mirror an adult’s (imagine fancy flashlights and finger puppets compared to the air puffs and letter reading you’re used to), it can provide a surprising amount of information about ocular health and vision both.
While this list is by no means comprehensive, this is a general guide to some of the main things being looked for when young children come in to have their eyes checked. There’s a method to the madness.
Refractive error: this is a fancier way of describing glasses prescription. While there is more leeway in what is “normal” at a young age, babies and children aren’t immune from the need for glasses. While a certain amount of farsightedness(hyperopia) is normal when younger, high amounts - or nearsightedness(myopia) or astigmatism prescriptions - need to be corrected to ensure both the vision is developing, and lower vision isn’t hindering a child’s development overall.
Anisometropia: tying in with the above, this is a big difference in refractive error between the two eyes. It’s the hardest to detect problems with at home, as often one eye is functioning perfectly while the other lags behind, so children seem to be seeing just fine. It is problematic in that vision in the eye with the worse prescription may not develop properly if not caught early enough.
Strabismus: This refers to eye turns of varying degree. While some eye turns correct on their own, or can be improved through patching and exercises, some require surgical intervention to get the eyes working together properly.
Amblyopia: Amblyopia is a catch-all term describing an eye that has vision that is underdeveloped - if permanent, even glasses cannot correct it down the road. It may be from a high glasses prescription, or an eye that lags behind/the brain ignores due to anisometropia or strabismus. If not caught before the age of seven or eight it may be irreversible.
Congenital cataract: Cataract refers to a clouding of the lens inside the eye. While it most often associated with older age, it can happen in infants as well. The lens normally focuses the light to the back of the eye, the retina, and if enough is blocked from coming through the eye cannot see properly.
Other: This list is much more extensive, and more rare. From serious tumours of the eye like retinoblastoma, to more benign problems like improper formation of the tear duct system, there are many eye health problems that need to be screened for early on. Premature birth can also cause eye complications, as can other systemic health conditions. Babies with Down’s Syndrome, for example, are at higher risk as well.
While the official recommendation for the first screening is six months old, a good rule of thumb is always to consult with your optometrist any time if you suspect problems at any age. The Government of Saskatchewan covers full eye examinations for children under the age of 18 annually through their health card, and covers more emergent problems at any age.
(*image credits to allaboutvision.com, ABC world news tonight, medicsindex.ning.com, main-line.co.uk)
Most contact lens problems aren't nearly so severe, but there are always serious risks to lens wear, especially when done improperly. Clean your contacts routinely, wear them according to instructions, and consult with your optometrist here at the Eye Gallery if anything starts to feel wrong!
Why do we insist upon frequently checking your eyes relative to your contact lenses, even if you seem to see fine?
For one thing, any eye health problems that arise from contacts can be asymptomatic until in late stages. Catching them earlier allows them to be treated, or prevented from progressing further by switching to different lenses or solution. Also, what was right for your eyes when you were fifteen isn't necessarily true later on. Your eyes change, and the technology of contacts also changes.
Via @SightGags on Facebook, be identified for your frame choices for the RIGHT reasons. Here at the Eye Gallery we are constantly getting in new frames, this time a completely new line called Mocha to add to our growing selection.
Ultraviolet rays, be it summer or winter, can be damaging to the eyes - increasing the risk of various conditions. From short term risks like minor burns to the front of the eye, to long term ones like increased chances of cataracts or macular degeneration, it is important to have proper eye protection year round.
Check your knowledge - below is a post clarifying what is fact, and what is fiction, about UV light.