Nearsightedness, medically called myopia, is a condition where you can see things up close clearly, but objects at a distance appear blurry. Reading a book or looking at your phone is fine, but a road sign across the street or a face down the hallway can be hard to make out. It is one of the most common vision conditions globally, and it affects people of all ages.<\/p>\n\n\n\n
The Canadian Association of Optometrists estimates that about 30% of Canadians are myopic, and that number has been climbing steadily, particularly among children and young adults. Rates are rising fast enough that eye care professionals now treat myopia management as a public health concern, not just a routine prescription matter.<\/p>\n\n\n\n
To see clearly, light that enters the eye needs to focus directly on the retina, the light-sensitive tissue at the back of the eye. In nearsightedness, the eyeball is too long or the cornea is too curved, so light rays focus in front of the retina rather than on it. That misalignment is what produces blurry distance vision. Everything beyond a certain distance starts to look soft or unclear, while anything held close stays sharp.<\/p>\n\n\n\n
Doctors classify this as a refractive error. It is not a disease but a structural variation in how the eye is shaped. That distinction matters because myopia itself does not damage the eye in most cases, though high levels of it can raise the risk of certain complications over time.<\/p>\n\n\n\n
Nearsightedness usually begins in childhood, between ages 6 and 12. During the teen years, as the eyeball continues to grow, it can develop or worsen quickly, and some teenagers need new glasses every 12 months or more. This is the window when regular eye exams matter most, since children rarely self-report vision changes.<\/p>\n\n\n\n
A 2018 study found that 6% of children aged 6 to 8 had myopia, and that figure jumped to almost 30% for children aged 11 to 13. For most people, myopia stabilises in the mid-twenties once the eyes stop growing. In some adults, it can continue to shift, particularly with heavy near work or prolonged screen exposure.<\/p>\n\n\n\n
There is no single cause. Both genetics and environment play a role, and in most cases it is a combination of the two working together.<\/p>\n\n\n\n
If one or both parents are nearsighted, the chances of a child developing myopia are higher. Beyond genetics, lifestyle habits are a significant contributor. People who spend long hours doing close-up activities, such as reading, detailed work, or extended screen time, are at greater risk. The eye adapts to near-focus demands over time, and for some people that adaptation leads to permanent elongation of the eyeball.<\/p>\n\n\n\n
Spending time outdoors appears to have a protective effect, and the research behind it is fairly consistent. A Canadian pilot study found that one additional hour of outdoor time per week lowered the odds of a child developing myopia by 14.3%. Natural light exposure and the visual demands of looking at distant objects in open spaces are both thought to contribute to that protective benefit.<\/p>\n\n\n\n
Myopia does not always announce itself clearly, especially in children who have never experienced sharp distance vision. A child with no frame of reference for clear far vision has little reason to report a problem, which is why symptoms are easy to miss without a proper exam.<\/p>\n\n\n\n
Common signs to watch for:<\/p>\n\n\n\n
Children with myopia do not always report blurry vision because it is all they have ever known, so routine eye exams are the most reliable way to catch it early. Adults who notice a gradual decline in distance vision should not wait for symptoms to worsen before booking an appointment with their optometrist.<\/p>\n\n\n\n
An optometrist can diagnose myopia during a standard eye exam. The process measures visual acuity at different distances and determines whether corrective lenses are needed and at what prescription strength. It is straightforward and non-invasive, typically involving reading letters off a chart and having a small light shone into the eye to assess how it focuses.<\/p>\n\n\n\n
Myopia is measured in dioptres. A prescription with a negative number, such as -1.50 or -3.00, indicates nearsightedness. The higher the number, the stronger the correction needed. Mild myopia sits below -3.00, moderate myopia falls between -3.00 and -6.00, and high myopia is anything above -6.00.<\/p>\n\n\n\n