Somayeh Heidarzadeh, M. Optom
Senior Training Manager, Vision Science Academy
Vision Science Academy Exclusive
Myopia, also known as near-sightedness, is a common vision condition that impacts how an individual sees objects. It is caused by a refractive error in the eye. A person with myopia can see objects that are at close distance clearly, but objects at a far distance appear blurry. The condition occurs when the shape of the eye causes light to bend incorrectly, focusing on images in front of the eye retina rather than images on the retina. The prevalence of myopic has surged exponentially in the past five decades and
the trend is projected to continue. In 1971, 25 percent of Americans had myopia. In 2004, the percentage increased to 33 percent and the percentage of people with myopia is projected to reach 54 percent (Ruiz-Pomeda & Villa-Collar, 2020). Glaucoma patients are at a higher risk for severe myopic symptoms because of their underlying eye conditions (Chen, et al., 2012). To manage the condition, several clinical trials have been performed to assess potential interventions that can slow down myopia progression.
How does multifocal contact lenses work?
A number of scientific studies have been conducted to evaluate the most effective interventions for slowing down myopia. A couple of studies show that multifocal contact lenses slow down the progression of myopia in glaucoma patients. Multifocal contact lenses are used to improve near vision individuals by correcting the near-sightedness to make the distance vision clear. Single vision prescription glasses only work to correct the myopic vision but do not treat the underlying issues that cause short-sightedness (Walline et al., 2013). On the other hand, multifocal contact lenses do not only correct myopic vision, but they also slow down myopia progression by slowing eye growth. Multifocal contact lenses have two primary parts that focus light on the eye. The centre part of the lens corrects short-sightedness to make the distance vision clear, thus focusing light directly on the eye retina. The other portion of the multifocal lens increases the focusing power to bring the bordering light rays into focus of the retina (Walline et al., 2013). On the contrary, single vision lenses and standard contact lenses do not stop the eye from growing because they focus the peripheral light to a focus point behind the eye retina causing the eye to keep growing. Research shows that multifocal lens provides effective slowing of myopia progression (Sankaridurg, 2017).
Myopia is a major risk factor for glaucoma and thus an effective intervention would help slow down the gradual loss of sight among patients with glaucoma. Multifocal contact lenses have proven to be effective in improving myopic condition and slowing down eye growth, which is a potential risk factor for total sight loss if left untreated. Myopia causes progressing degeneration of retina, which may eventually cause total loss of sight. As a result, multifocal contact lenses help to correct the refractive error in the retina caused by imbalance in the eye shape. Furthermore, multifocal contact lenses not only improve eyesight, but also slows down its growth.
Chen, S. J., Lu, P., Zhang, W. F., & Lu, J. H. (2012). High myopia as a risk factor in primary open angle glaucoma. International journal of ophthalmology, 5(6), 750.
Ruiz-Pomeda, A., & Villa-Collar, C. (2020). Slowing the progression of myopia in children with the MiSight contact lens: a narrative review of theevidence. Ophthalmology and Therapy, 9(4), 783-795.
Sankaridurg, P. (2017). Contact lenses to slow progression of myopia. Clinical and experimental optometry, 100(5), 432-437.
Walline, J. J., Greiner, K. L., McVey, M. E., & Jones-Jordan, L. A. (2013). Multifocal contact lens myopia control. Optometry and Vision Science, 90(11), 1207-1214.