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Impact of Loupes and Lights on Visual Acuity and Ergonomics

Using loupes and lights may help clinicians compensate for visual deficiencies and improve ergonomics, possibly increasing career longevity.

Visual acuity is imperative to performing precise movements during clinical care and sustaining proper ergonomics. According to the American Optometric Association, visual acuity refers to the clarity or the sharpness of vision.1 Dental hygienists perform clinical care in the oral cavity with a restricted field of vision due to limited space and lighting.2,3 As part of clinical practice, dental hygienists use visual motor integration to control eye and hand coordination to perform precise movements.2–4 When visual acuity is deficient, it impacts a dental hygienist’s ability to accurately assess disease of the hard and soft tissues, read the periodontal probe, and evaluate radiographs, among other challenges.2,5,6 Further­more, visual acuity declines with age, and dental hygienists may compensate their ergonomics to enhance their field of vision.7

FIGURE 1.Head Tilt and Neck Flexion Range
FIGURE 1.Head Tilt and Neck Flexion Range11

Impact of Visual Acuity on Ergonomic Practice and Health

Ergonomic health and visual acuity are topics of concern for dental hygienists.8,9 Dental hygienists are practicing longer and relying on the overall strength of their bodies to increase their work longevity. Visual deficiencies may impact postural positioning, compromising ergonomic health and increasing the risk for musculoskeletal disorders (MSDs).3,4 The risk for MSDs is increased by prolonged static positions, repetitive instrumentation, and limited field of vision.2–4 MSD-related pain and injury are associated with the number of hours practiced weekly, and often affect the spine, shoulders, and neck.3,8 Because dental hygienists are remaining in clinical practice longer, the clarity and sharpness of vision are of even greater importance as poor vision affects postural positioning and, ultimately, compromises balance.2 

Visual deficiencies may result in the head tilted forward, over-exerted neck flexion, and lack of balance. A neutral neck position should be maintained during clinical care, which encompasses a head tilt range of 0° to 15° and a neck flexion of 0° to 20°. Dental hygienists’ neck flexion is often beyond 20°, causing neck pain (Figure 1).3,10,11 In addition, for every inch the head is tilted forward and the neck is flexed, the weight of the head also increases.12 This adds additional stress and strain to the cervical muscles of the neck and initiates a domino effect of abnormal forces to the spine, compromising ergonomic health.13 

Maintaining a neutral neck position can be challenging as visual acuity declines with age. The risk of visual deficiencies—such as presbyopia, or farsightedness—increases especially among clinicians older than 40. Presbyopia is caused by the loss of elasticity in the lens of the eye, which makes it challenging to focus on objects in close range.7,14 

Dental hygienists maintain a short working distance from the oral cavity (27 cm to 50 cm), which requires clarity and sharpness of vision.1,15 Clarity and sharpness are not only required for clinical patient care, but for other tasks as well, such as viewing radiographs or computer monitors farther away. In addition, the expansion of electronic displays in dental settings, as well as prolonged personal electronic use, enhances eye strain, discomfort, and ocular surface changes.16 Visual deficiencies caused by age and blurred vision from presbyopia impact the ability to focus on objects in various ranges during patient care. 

Loupes and Lights for Improved Visual Acuity and Ergonomic Practice

The use of loupes is an evidence-based strategy to improve clinical performance and ergonomics.17–19 In dentistry, both Galilean and Keplarian telescope systems are used. The Keplarian prismatic loupes have a higher magnification compared to the Galilean. Because of their 3.5x up to 8.0x magnification, Keplarian loupes have longer barrels and are heavier than Galilean loupes. Galilean loupes, which are the most commonly used for dental hygiene procedures, offer a magnification range from 2.0x to 3.5x. With a concave lens and a convex lens, Galilean loupes produce a more distinct image than a single lens.20

Dental hygienists are relying on the overall strength of their bodies to increase their work longevity.

Panoramic loupes with a 3.5x magnification are also available. The panoramic lens is rectangular, allowing for increased peripheral vision, doubling the Keplarian prismatic viewable area. This type of loupe may be ideal to see more teeth at one time. 

The use of loupes improves ergonomics and reduces the risk of MSDs.6,9,21,22 Additionally, the greatest advantage of loupes are enhanced indirect vision, improved vision for instrumentation, and reduction of visual deficiencies among clinicians older than 40.2,6,7 Other advantages include improved ability to read the periodontal probe, assess soft tissues, and detect calculus. The combination of loupes and lights enhances dental hygiene assessments and improves quality of care by illuminating the oral cavity.23,24 The literature, however, is limited on the impact of loupes on treatment outcomes.9 

Loupes, when properly fitted, should be considered a foundational component to musculoskeletal health. Dental hygienists have reported less pain in their shoulders, arms, and hands after using loupes for only 6 months.8 Thus, introducing loupes early into dental hygiene education may reduce visual deficiencies, thus decreasing the risk of MSDs. Enhancing magnification with improved illumination from a head light improves visual acuity and supports balance. 

Disadvantages of Loupes and Lights on Ergonomic Practice and Musculoskeletal Health

The use of loupes and lights is not without disadvantages. While wearing loupes, a dental hygienist’s sensorimotor may be altered due to the eyes shifting from magnified to nonmagnified fields, making it challenging to maintain balance and a neutral neck position. The early changes in magnification fields may cause ­vertigo and eye soreness. Dental hygienists should know that the adjustment period for wearing loupes is usually 2 weeks to 3 weeks.25–27 

Illumination from a head light improves visual acuity and supports balance.

Both the Galilean and Keplarian loupe lenses can be mounted onto the front of the frame as a “flip up” or entrenched into the spectacle lens itself, which is known as a through-the-lens (TTL) loupe. For dental hygienists with prescription glasses, the flip-up loupe is best because the prescription lenses can easily be placed in and out as needed. The flip-up loupe, however, is heavier than the TTL loupe. Although the fixed TTL loupe is lighter, it is also more expensive, and dental hygienists do not have the ability to easily switch between magnified and direct vision.

The weight and cost of loupes and lights are also potential barriers. Loupes cost between $600 and $1,200 and lights range between $300 and $600.6 In regards to ergonomic health, the additional weight poses risks as well. Keplarian telescope systems provide a higher magnification, but are heavier and more expensive than Galilean loupes. In addition, LED headlamps add weight. Most LED headlamps require an attached battery pack that powers the light, which may cause cross-contamination risks. At certain intensities, the LED illumination may also harm the retina. It is important to verify that a headlight’s LED beam has white or colorless beams.28 

The type of loupe and light purchased depends on the user’s individual needs. Loupes must be properly adjusted to conform to the dental hygienist’s facial features. Even the smallest fitting error can cause eyestrain.29 In addition, headlight systems greatly vary between manufacturers. Most loupe manufacturers make both cordless and corded batteries. Lights with corded batteries are often lighter on the frame. 

As light intensities can vary, dental hygienists need to inquire about illumination products that will be both safe and comfortable. Dental hygienists should educate themselves on loupe and light brands and seek professional assistance for customized fitting before making a purchase. Other factors to consider when purchasing loupes are cost of accessories and replacement parts, as well as ease of maintenance and after-sales care. 


Dental hygienists wishing to extend their careers will need to maintain ergonomic health. Visual acuity is necessary to perform clinical care and sustain proper ergonomics. Dental hygienists need to be aware of visual deficiencies and the natural process of declining vision with age. Considering the effect of visual acuity on clinical care and ergonomics, practicing dental hygienists should have their near vision evaluated regularly. The addition of loupes and lights may compensate for visual deficiencies and improve ergonomics, allowing dental hygienists to enhance patient care and maintain the longevity of a clinical career. 


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  12. Kapandji AI. The Physiology of the Joints: the Spinal Column, Pelvic Girdle and Head. 7th ed. Pencaitland, Scotland: Handspring Publishing Ltd; 2019:1–359. 
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From Dimensions of Dental Hygiene. August 2021;19(8):21-23.

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