Since May is Healthy Vision Month, now is a good time to discuss and learn more about vision problems and what can be done to correct them. Throughout the various stages of our lives, we can be prone to different vision problems and eye diseases. From infancy to living as an adult over the age of 60, here are some of the most common vision issues at each stage of life and the care and attention they require.
Strabismus- a condition that usually affects babies that are older than 3 months, it is characterized by a misalignment of the eyes preventing normal binocular vision. It is normal for all people regardless of age to converge their eyes when looking at something close. Infants usually develop normal fused binocular vision by the age of 6 months. Therefore, it is recommended that infants have their first eye exam at this age. Strabismus can often be corrected with glasses if your child is farsighted and an esotropia is present. Esotropia describes the situation when the eyes converge or turn in too much. Exotropia is the strabismus where one eye is pointed outward. The most common form is called exotropia of divergence excess. It can be corrected in some cases with glasses when a refractive error is the cause of poor binocular coordination. Exotropia may also be corrected with muscle training called orthoptics. Some forms of strabismus ultimately require surgical correction, which uses muscle shortening or muscle reinsertion into the eye to achieve binocular alignment.
Amblyopia- also called lazy eye, this is when one eye is weaker than the other and is usually a direct result of strabismus, but can also develop in the presence of an uncorrected vision deficit that affects one eye more than the other (usually this occurs when one eye has a prescription greater than the other by more than 1 dioptre, and more often seen in cases of hyperopia or astigmatism as opposed to myopia). When cross-eyed develop in adulthood, diplopia or double vision is appreciated. This is often associated with stroke, but can also be the result of less serious issues. When this happens in infancy, if it is not corrected quickly could lead to the brain ignoring the visual info from the deviated eye and this can lead to lazy eye. A lazy or amblyopic eye is an eye that cannot see to the normal level of 20/20, even with the best possible vision correction in place. Amblyopia is often treated through patching the dominant or stronger eye, forcing the brain to use the weaker eye’s information and start to lay the neural networks that strengthen the eye-brain connection.
Hyperopia– this vision condition is normal in infants and children up to the age of 7. High hyperopia or significant asymmetry in the amounts of hyperopia can lead to amblyopia, headaches, attention deficit and learning difficulties. Hyperopia is present when the relaxed eye’s focusing is too weak for the length of the eye. Hyperopia can be compensated for by using accommodation. When this is not adequate or sufficient to prevent symptoms or the development of lazy eye, glasses are prescribed.
Myopia- probably the most common vision problem in children and one whose incidence is on the rise, is also called nearsightedness and is characterized by the inability to see things at a distance clearly. The distance at which objects become blurry depends on the level of myopia. It is especially impactful in children because good eyesight is key for learning in school. The most common treatment for myopia in children is corrective glasses, and as children approach their teenage years contact lenses become an increasingly popular alternative to glasses. At least 2 hours of outdoor activity is recommended to reduce the incidence and progression of myopia in growing children.
Conjunctivitis- also called pink eye, this is a viral or bacterial infection that affects the mucous membrane covering the outer eye. Your child’s eye will be red or pink, discomfort/itchiness may or not be present as well as any discharge. Since conjunctivitis has many possible causes, including allergic or contact lens induced, any red eye should be investigated and treated appropriately to avoid discomfort, spreading the condition and even possibly permanent vision loss. Self diagnosing and treatment with over-the-counter remedies is never a good idea due to the possibility of permanent vision loss.
Astigmatism- this problems results in blurred vision at all distances, but often with symptoms of blurred vision at a further distance and eyestrain, or asthenopia, with near vision tasks. It is often the result of a football-shape of the cornea and is most common in teenagers. It can be corrected with prescription eyeglasses or contact lenses.
Presbyopia- this is by far the most common vision problem among adults over 40. Near vision focus starts to blur (the process of weakening near focusing otherwise known as accommodation begins in our twenties and finally captures up to us in the fourth decade of life) and the ability to do things such as read, sew and work on the computer becomes more difficult. The most common treatment for presbyopia are eyeglasses, but multifocal contact lenses are becoming an increasingly popular method of correction. Reading glasses are worn for close-up reading and other near vision tasks. Bifocals or progressive lenses (i.e.. invisible bifocals with a power progression) are special lenses that are made with two or more points of focus, for both near and far vision correction. Progressive near lenses are like conventional progressives, but they offer a range of near vision focus for people with more advanced presbyopia that want a range of near vision, such as from the computer screen (arm’s length) to regular reading distance (usually 16 inches).
Adults over 60
Cataracts- the internal lens of the eye naturally clouds as we age. This is called a cataract. Not all cataract lenses need to be surgically removed. When the cloudiness begins to cause vision or lifestyle issues, even in the presence of the best most up to date prescription possible, then it is time for the cataract to be removed. The cloudy lens is replaced with an implant called an intraocular lens to replace the power of the natural lens. Today’s implants can correct both hyperopia, myopia, astigmatism and also are available in multifocal modalities.
Age-related Macular Degeneration (AMD) – this disease is characterized by central vision loss due to aging and breakdown of the photoreceptors in the macula (the area of the light-sensitive retina found at the back of the eye). Only central vision is affected, with peripheral vision remaining intact. Unfortunately, it is the macula that is responsible for our most detailed vision, such as reading, color perception and facial recognition. AMD can be treated with anti-vasogenic drugs, but there is no cure.
Good vision is important no matter what age we are, so remember to take good care of your eyes by wearing sunglasses, leading a healthy life style and eating lots of dark green, leafy vegetables and fruits, and of course having regular, routine eye health and vision exams!
Credit to Dr. Jeff Sciberras – Mississauga Optometrist