March 14, 2018
Fun fact: all human vision is about the refraction of light. That’s kind of neat when you think about it. Think about the diversity of the objects you see around you, or those in a nature documentary: the variety, the color, the shapes.
How we see fundamentally comes down to the way our eyes interact with light in our environment. As Isaac Newton demonstrated with a triangle of glass in 1672, refraction is about how a wave (in this case light) interacts with a clear or opaque surface (in this case the structures of our eyes). And the results of refraction allow for the vision differences we see with rainbows, diamonds or eyeglasses.
Most cases of blurry vision are caused by the refraction of light entering the eye, more commonly known as “refractive error”. Refractive error conditions include myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia (reading vision). Hyperopia and presbyopia are two extremely common such variations, and they both relate to the shape of the structures in your eyes. While similar conditions, they aren’t identical.
Hyperopia is the clinical term for what people commonly refer to as farsightedness. It happens when light refraction is altered by an eyeball shape that prevents light from properly projecting onto the retina. It effects 5-10 percent of the population, and those who have it are more easily able to distinguish details or objects that are further away than they are when they’re up close. In mild cases, especially in kids, farsightedness might not even be something they notice much.
However, it can cause symptoms such as eye strain, squinting, headaches, and blurry vision, and they are likely to get worse with time as part of the normal aging process. The more severe the hyperopia, the more likely the symptoms are to affect wellbeing and comfort.
Presbyopia is slightly different. As people age, the lens of our eye hardens. As this happens, the eye refracts light differently, and again, it doesn’t directly hit the retina. At the same time, muscles around the eye weaken. As a result, it becomes increasingly difficult to focus on up-close objects.
While Hyperopia is a product of genetic or environmental chance, and can manifest at any age, Presbyopia is basically unavoidable. Most people will begin to notice it around age 40, as close-up objects like books, smartphone screens, or even closely examined photos become blurrier.
The good news is that, thanks in part to that work on refraction by our old friend Isaac Newton, hyperopia and presbyopia can both be treated with glasses or contacts. Convex lenses are the solution as they bend the light entering the eye, making small prints easier to read (similar to a magnifying glass). Lasik is also a permanent treatment solutions for hyperopia. Here are some tips on how to find reading glasses that work for you.
What works best for you will depend on the specifics of your eyes, which we can measure, using the EyeQue Personal Vision Tracker. What kind(s) of corrective lenses you need depend on the unique measurements of your beautiful baby blues, or fawn browns, or emerald greens, or dashing hazels.