Presbyopia vs myopia: impact on vision, prevalence, onset age, and treatment approaches.
Refractive errors, including myopia and presbyopia, occur when the eye fails to focus light correctly on the retina. The intricate interplay of factors such as eyeball length, corneal shape, and age-related changes in lens flexibility contributes to these visual anomalies.
This article delves into the distinct characteristics of myopia and presbyopia, highlighting both their differences and similarities.
Different types of refractive errors
Refractive errors simply refer to vision problems that occur when your eye doesn't allow light to focus correctly on the retina.
There are four common types of refractive errors:1
- Myopia, or nearsightedness, makes far-away objects look blurry
- Hyperopia, or farsightedness, makes nearby objects look blurry
- Astigmatism, which can blur or distort both distant and nearby objects
- Presbyopia, age-related farsightedness, makes nearby objects look blurry and can happen with myopia at the same time.
These errors can occur due to various factors, such as the length of your eyeball, the shape of your cornea, or the loss of flexibility in the lens of your eye due to aging.
Myopia typically occurs when the eyeball is too long or when the cornea is excessively curved. This causes light to focus in front of the retina, resulting in blurred distance vision. On the other hand, anatomical changes that lead to light focusing at the back of the retina, which is the opposite of myopia, is hyperopia.
Individuals with myopia require vision correction with a prescription that has a minus power. On the other hand, hyperopia is characterized by a need for vision correction with a prescription that has a positive power. A zero power means no vision correction.
Hyperopia is often present from birth, and the body usually self-corrects to achieve normal vision in childhood. However, in the case of myopia, the self-correction process can overshoot into the minus power.
Presbyopia, on the other hand, is an age-related condition that occurs when the lens of the eye becomes stiff and loses its flexibility. This makes it challenging to adjust focus when transitioning from near to distance vision.
Presbyopia typically develops in individuals in their 40s and can occur even if they have other refractive errors, including myopia. Similar to hyperopia, presbyopia is corrected with a prescription that has a positive power.
(Learn more about how to read a vision prescription)
Presbyopia vs Myopia
Presbyopia and myopia display distinctions in three vital aspects. While presbyopia is highly prevalent, affecting nearly all older adults, myopia commonly begins in school-aged children. Presbyopia is characterized by the lens not functioning optimally, resulting in blurriness for objects up close. In contrast, myopia is often attributed to the elongation of the eyeball or excessive corneal curvature, causing distant objects to appear blurry.
Prevalence and Age: Myopia commonly manifests in school-aged children, with 42% of adults in the US reported to have myopia.2 In contrast, presbyopia is an inherent part of the aging process, typically beginning after the age of 40, affecting nearly everyone.3
Eye Structure: Presbyopia is characterized by the hardening and reduced flexibility of the eye's lens with age, leading to challenges in focusing on nearby objects. Conversely, myopia results from either an elongation of the eyeball or excessive curvature of the cornea, causing light to focus in front of the retina rather than on it.1
Vision: Presbyopia impacts the ability to see objects up close, such as reading a text message or a label on a medicine bottle. On the other hand, myopia causes distant objects to appear blurry, posing challenges in tasks like reading road signs while driving or viewing the blackboard in a classroom.1
Treatments for presbyopia vs myopia
The primary objective of treating presbyopia and myopia in adults is to enhance clear vision. Here are various options for each condition:
Presbyopia treatments for adults
- Corrective eyeglasses or contact Lenses: Single-vision reading glasses are specifically designed for close-up activities like reading. If an individual has both presbyopia and myopia, the consideration of bifocal or progressive eyeglasses, or multifocal contact lenses, becomes relevant. These options offer a combination of prescriptions, addressing both near and distance vision requirements.1
- Vuity and Qlosi Eye Drops: These eye drops contain pilocarpine, a miotic that targets specific eye muscles, causing them to contract. This muscle contraction helps the lens of the eye change shape, creating a pinhole effect and allowing for better focus on nearby objects.
- Intraocular Lens Implant: This is an option usually considered when also treating cataracts. For people with myopia, multifocal intraocular lens is also available to correct both myopia and presbyopia at the same time.1
- Refractive Surgery (Mono/blend-vision): These specialized surgery, aims to minimize reliance on reading glasses. It involves correcting one eye for distance (emmetropia) and the other for near vision (myopia). It's essential to note that some patients can only significantly reduce their dependence on reading glasses but not completely eliminate their use.1
Myopia treatments for adults
- Eyeglasses or Contact Lenses: Corrective lenses, whether in the form of eyeglasses or contact lenses, can effectively compensate for the blurred distance vision associated with myopia.1
- Refractive Surgery: Surgical interventions like LASIK or PRK are commonly employed to reshape the cornea and correct myopia, offering a more permanent solution.1
- Intraocular Lens Implant: Similar to presbyopia treatment, an intraocular lens implant is considered for myopia, particularly when cataracts are also present.1
Interestingly, some people with myopia, especially those with low myopia (-3.00 D or less), may find they can 'self-treat' presbyopia by simply removing their glasses. As the prescription for correcting presbyopia is usually between +1.00 to +3.00 D, it could be a simple and workable solution for people with low myopia.
Myopia treatments for children
Treatment options for myopia in children may differ from those in adults, as the primary goals are not only achieving clear vision but also preventing progression. Surgical options are often inappropriate due to the ongoing development of children's myopia. The following treatments are commonly utilized:1
- Eyeglasses or Contact Lenses:1
- Standard treatment involves wearing glasses or contacts.
- While regular glasses alone don't slow abnormal eye elongation, they can complement interventions like atropine.
- Not wearing glasses was shown to lead to faster myopia progression.
- Atropine:1
- Low-concentration atropine eye drops, used nightly, have shown promise in preventing myopia onset and slowing eye elongation.
- Despite proven effectiveness and safety, regulatory approvals (e.g., FDA or EMA) may be lacking due to the absence of patent protection.
- Specially designed glasses correct nearsighted vision and slow abnormal eye growth.
- Unlike regular glasses, they have a correction area in the center and a myopia control area for the desired effect.
- Myopia Control Soft Contact Lenses:1
- Similar to myopia control glasses, these lenses have both a correction area and a myopia control area, usually available as daily wear lenses.
- Involves using specially designed hard contact lenses that reshape the cornea.
- Worn at night, they provide temporary correction the next day while slowing abnormal eye elongation.
Summary
In summary, addressing refractive errors involves tailored treatments based on specific conditions. Presbyopia and myopia, distinguished by prevalence, onset age, and impact on vision, require different approaches.
For adults, treating refractive errors focuses on correction. Common options for presbyopia include corrective eyeglasses, contact lenses, and eye drops. Myopia treatments in adults include eyeglasses, contact lenses, refractive surgery, and intraocular lens implants.
In children, the treatment goal for myopia is to correct refractive errors and prevent progression. Treatment options comprise eyeglasses, atropine eye drops, myopia control glasses, myopia control soft contact lenses, and orthokeratology.
Related articles:
1. Can you have both farsightedness and nearsightedness at the same time?
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- Jacobs, Deborah S et al. “Refractive Errors Preferred Practice Pattern®.” Ophthalmology vol. 130,3 (2023): P1-P60. doi:10.1016/j.ophtha.2022.10.031
- Holden BA, Fricke TR, Wilson DA, Jong M, Naidoo KS, Sankaridurg P, et al. Global prevalence of myopia and high myopia and temporal trends from 2000 through 2050. Ophthalmology. 2016;123(5):1036–42.
- Patel I, West SK. Presbyopia: prevalence, impact, and interventions. Community Eye Health. 2007;20(63):40-41.
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