Eyes are complex organs made of many important parts. When viewing the world around us, we are heavily relying on our eyes’ ability to refract light. Light from objects passes through the cornea and lens which refract, or bend, the light onto the retina to create the image in the brain. Refractive vision errors result from changes to the shape of the eye which causes problems with sight.
Refractive errors that distort vision
Astigmatism, myopia, hyperopia, and presbyopia are types of refractive vision errors that can happen to anyone, but they are often genetically determined. Refractive errors can be caused by problems with the shape of the cornea or lens, the eyeball growing too long or too short, or just the general aging of the eyes.
Untreated refractive errors are the leading cause of vision impairment and the second most common cause for blindness worldwide, finds a recent study. Vision issues must be taken seriously and corrected, as poor vision can lead to lost employment opportunities, additional health issues like headaches and strain, and impacted quality of life. The 2020 Vision Loss Expert Group, in research published in The Lancet, estimates that more than 86 million people worldwide have moderate or severe vision impairment due to uncorrected refractive errors.
While at work, poor vision leads to loss of productivity and a higher chance for mistakes. The United States Occupational Safety and Health Administration (OSHA) estimates that workplace eye injuries can lead to an estimated $300 million a year in lost productivity, medical treatment costs and worker compensation. Vision impairment can also have disastrous results, from eye injuries to long-term damage and blindness. Workers often depend on their eyesight to do their jobs to the best of their abilities.
Astigmatism is a common refractive vision error resulting from an abnormal shape of the cornea or lens. In this condition, the eye does not focus light evenly on the retina, rather the focal point of the light is distorted. This causes objects up close or a further distance to appear blurry or distorted.
People with astigmatism may also have trouble seeing at night or need to squint to see clearly. It may also be combined with nearsightedness or farsightedness. People can be born with astigmatism or develop it later in life. A dilated eye exam can be used to check for astigmatism. Fortunately, astigmatism can be corrected with prescription eyewear, but if left untreated, can result in headaches and eye strain.
Myopia — nearsightedness
Myopia is a refractive error that makes distant objects appear blurry or out of focus; it’s commonly known as nearsightedness, meaning you can see things that are nearby easier. Myopia results from problems with the shape of the cornea or lens or from the eyeball growing too long from front to back. This causes refracted light to focus in front of the retina, rather than on it. Symptoms include trouble seeing things far away, eye strain, and squinting to see.
Nearsightedness has genetic connections -- often people in the same family will have the same vision issues. But it’s also regulated by visual feedback from our environment. Myopia usually starts to become prevalent in children, between the ages of 6 and 14, and then gets worse with age. The number of people with myopia has been rapidly increasing worldwide.
High myopia, which causes severe nearsightedness, can put someone at risk for other severe conditions like retinal detachment, glaucoma, cataracts, or macular degeneration. Prescription eyeglasses help to correct myopia by adjusting the focus to the retina. Proper eye care should both correct far vision and reduce strain for nearer objects. People with myopia often prefer eyeglasses as they can be put on during specific activities, like reading or working on a computer.
Hyperopia — farsightedness
In contrast to myopia, hyperopia causes nearby objects to appear out of focus and further objects may be easier to see. Commonly known as farsightedness, hyperopia causes the light emitted into the eyes to be focused behind the retina. People with farsightedness may have trouble reading or experience eye strain and headaches. There also may be an aching or burning sensation around the eyes, especially when trying to focus on something for a long time.
Unlike myopia, people will often have hyperopia from birth yet don’t have vision problems until they are older. Some adults with hyperopia may have trouble seeing things both near and far. Hyperopia is corrected with convex prescription lenses, which are thin around the edge and thicker at the center to restore vision.
Presbyopia — age-related difficulty focusing up close
Not everyone will have the above three refractive vision errors, yet everyone may develop presbyopia, usually after age 45. As we age, the lens of our eyes becomes harder, and has a more difficult time focusing.
Presbyopia is the most common cause of vision impairment -- presenting in approximately 510 million people around the world. People with this refractive vision error have difficulties seeing things up close, such as a computer screen, and may develop headaches and eye strain.
Prescription eyeglasses with progressive or photochromic lenses are used to treat presbyopia. Bifocal glasses are literally separated in two, with the top half designed for seeing far distances and the bottom for reading. Trifocals add an extra section for mid-focus work, like using a computer or a tablet.
Treating refractive vision errors with prescriptive eyewear
Refractive vision errors affect everyone, yet leaving these issues uncorrected can lead to numerous negative impacts, including related health concerns. Vision concerns in the workplace can lead to accidents, injuries, and long-term impacts to the life and career of workers.
Advances in vision care have brought a range of prescription eyeglass options for people with refractive errors, reducing vision impairment and leading to more productivity and a better quality of life and work. Companies have a say in this battle. They can improve employees' wellbeing and productivity by treating visual impairments through prescription eyewear programs.
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