Focus on Fundamentals

Sports eyewear might seem like a niche offering with an intimidating list of specifications based on different styles and sports. While it might not seem an essential part of your daily optical repertoire, having a foundational knowledge of the fundamentals that set sports eyewear apart from traditional eyewear and sunglasses will give you, the eye-care professional, the confidence to make the recommendation to clients and not only increase your multipair sales, but also show your commitment to your patients’ eye safety.

What sets sports eyewear apart from regular glasses and sunglasses is not only the physical appearance of the eyewear but also the standards for safety and impact resistance the frames and lenses must meet.

Sports eyewear can be broken down into two main categories: performance and safety-based. While there is crossover in some characteristics, sports eyewear that meets the highest level of safety is categorized and labeled as ANSI Z87.1, offering the wearer protection from eye injury.

The Patient Question Lineup

The key to knowing how to recommend and fit sports eyewear is to uncover the patient’s need for it in their lives through two simple questions that can reveal so much.

“Do you require prescription correction?”

Knowing if your patient has prescription correction needs will determine if the requirements are for plano or prescription sports eyewear. Plano sports eyewear comes without limitations, while prescription sports frames must be carefully selected to ensure Rx compatibility.

Fast-paced action sports and activities are best and most safely played in single-vision lenses. Sports and activities such as cycling and hiking can require GPS and tech equipment use, in which the wearer would benefit from a multifocal if they are presbyopic.

“What sports or activities do you participate in?”

Knowing what sport(s) and activities your client participates in allows the ECP to make recommendations based on the level of eye safety protection required and will identify if the sport is played indoors, outdoors, or both, leading the ECP to make a recommendation based on if the lenses should be clear, tinted, or photochromic.

Other Considerations

A common characteristic of sports eyewear is a frame style with a wrap design, a high-base-curved lens, and a larger lens silhouette, offering the performance-based benefit of a wide field of vision without peripheral interference or occlusion and the safety-based benefit of a close-to-the-face fit that prevents wind, dust, debris, or objects from entering the eye.

When fitting plano or low Rx +/-2.00 diopters, a wrap style and low base curve offers minimal negative effect on the wearer’s visual experience, but as the Rx power increases or an add power is introduced, the base curve can induce a negative effect on peripheral vision. This is where sports frames with side shields can offer the same protection and reduce the need to have a lens with a high base curve as some patients cannot tolerate the visual effects.

Knowing how your patient’s Rx will affect the overall wrap angle of a frame is also worth noting. An 8-base wrap frame may fit perfectly snug in a plano lens style for your patient, yet when fitting with their -6.00-diopter lens, the overall wrap angle would splay and may lead to a frame that is now loose and ill-fitting, if the lens style cannot be made in a matching 8 base.

Lens Calculation Tools

The Lens Clock

A lens clock measures the curvature of a lens and can be used to determine the base curve of an optical lens. By gently pressing the stylus against the lens, the measurement is the distance from the base of the lens clock to the highest point on the lens. The display will show the base curve value of the lens.

Frame Wrap Angle Measuring Chart

A frame wrap angle measuring chart is a helpful tool that allows the ECP to simply place the frame on top of it to determine the overall wrap angle of the frame. It is an especially helpful tool to use when ordering lenses for sports wrap frames to ensure that the lenses are cut and shaped accurately to achieve the desired wrap angle.

Lens Blank Size

Formula Sports frames with wrap typically require larger lens blanks. For this reason, calculating the required lens size and specifying this when ordering the lenses prevents cutout issues and reduces manufacturing time. Calculating MBS (minimum blank size) can be done with the following formula MBS = ED + (2)(per-lens decentration) + 2mm or by using an online calculator for MBS (opticampus.opti.vision/tools/blanksize.php).

Many lens manufacturers now offer sports-specific single-vision and multifocal lens options that allow for greater base curve compatibility with a broader range of prescriptions and larger lens blanks to accommodate oversized ED (effective diameter) measurements, which reduces cutout issues.

Sports eyewear is an additional optical product that a large percentage of clients would benefit from, offering the wearer improved performance and enjoyment during sports and athletic activities, all while providing safety and protection from injury. Having a base knowledge of the guidelines and requirements for fitting and dispensing sports eyewear will result in additional use of the knowledge and lead to greater abilities as an ECP.