About 90 million Americans, or 35% of the population across all age groups, avidly participate in some sort of sport, while another 84 million participate in a sport occasionally, according to the Sporting Goods Manufacturing Association.

These athletes may have special visual needs for which you can provide. Consider: A sports vision epidemiology project conducted by the Sports Vision Service at the Illinois Eye Institute, Chicago, found that of 939 athletes competing at various levels of competition, 25% had never had a complete eye examination, 29% had visual symptoms, and 28% had less than 20/25 acuity through their habitual sports prescription.¹ These results indicate that athletic populations at all levels are in need of eye-care services, the researchers concluded.¹

Not only that, but the demands on the visual system during athletic performance have been described as “among the most rigorous of any activity,” and vision influences the capacity of an athlete to perform the tasks of a sport.² Most sports vision research efforts have been directed toward identifying the visual skills needed for sports and determining if the skills of athletes differ from those of non-athletes. These efforts, though incomplete, have suggested that certain visual skills are important to performance in selected sports and that the visual skills of athletes and non-athletes do differ.

A sports vision specialty can serve not only as a practice builder, drawing a new population of patients, but can provide needed eye services. For those of you looking to establish a sports vision specialty, we’ll review the levels of care and discuss the evaluation and management of these patients.

Levels of Care

When providing sports vision services, you can provide sport-specific refractive and ocular health care to high school or college athletes. Or, you can court professional teams with comprehensive care, including office-based vision therapy and periodic videotaping of individual athletes.

A basic level of care usually entails providing exams and vision correction with contact lenses or glasses. In addition, you provide the athletes with emergency treatment for eye injuries they may sustain during the sports activity. This level of care should include counseling on protective eyewear, sunwear, performance tints and education/referral for refractive surgery.

At moderate levels of care, the practitioner offers everything involved at the basic level, with the addition of home-based vision therapy activities. At this level of care, the expectation is that the vision therapy techniques are very simple, easy to perform and easy for the athlete to understand.

Comprehensive care includes everything offered at the basic and moderate levels, plus a tailored office-based vision therapy program and a video critique of each player’s visual performance during his or her sport.

Dr. Hefner works with a tennis player, emphasizing the importance of following the ball when swinging the racquet. A Marsden ball, a suspended rubber ball used to develop tracking skills, eye-hand coordination and more, was used.

Parameters of Sports Vision

Evaluating the vision of an athlete involves more intensive testing than you perform on other patients. It requires a greater understanding of how the patient’s visual system reacts under extreme and less-than-optimal circumstances, as well as how the visual system coordinates with body movement.

Many of these elements have been brought together in the Pacific Sports Visual Performance Profile (PSVPP). This profile was pioneered by optometrists Bradley Coffey and Alan W. Reichow of Pacific University College of Optometry. Their goal: to standardize the visual performance of Olympic-level and professional athletes. An understanding of the individual elements that make up PSVPP provides a better understanding of the various skills necessary in the most common sports as well as some of the goals of sports vision therapy. Although not practical in every practice setting, the PSVPP can serve as a reference list of skills that should be assessed on all athletes.

The PSVPP consists of the following measurements:

• Static and dynamic visual acuity. Static acuity is normal visual acuity measured with the Snellen chart. Dynamic visual acuity is visual acuity measured with a moving target.

• Contrast sensitivity. This is the ability to discriminate targets under various lighting conditions or contrast levels. An example of a low-contrast target: a white baseball against a gray sky.

• Accommodative and vergence facility and vergence ranges. Accommodative facility refers to the ability to quickly change the focusing of the eyes when looking between objects at different distances. Vergence facility is the ability to quickly change where the eyes are pointing when looking between objects at different distances. Vergence ranges represent the ability to turn both eyes inward and outward at both 40cm and at 6m (20 feet).

• Stereopsis. This measures depth perception at 6m.

• Central visual recognition. This is the ability to recognize, evaluate and differentiate an object, such as the difference between two teams' uniforms, very quickly.

• Eye-hand, eye-foot reaction speed and coordination. These represent the speed and dexterity at which visual information can be transformed into action.

• Vision and balance. This measurement considers how the body and vision work together. An example: an athlete’s ability to catch a ball while standing on a balance beam. This would be particularly useful to the wide receiver who is often catching a ball while “tip-toeing down the sideline” or in the back of the end zone.

There are numerous methods for testing all these visual skills (as well as a few others). Also, numerous eye exercises allow athletes a chance to practice the visual skills they require for their particular sport. These exercises, which may be used at home or in the office, emphasize visual recognition, motor coordination, and concentration.³

Home exercises that are commonly employed include the Brock string, flip-card exercises, and ball on a string (Marsden ball). Office exercises usually include the use of specialized equipment such as the tachistoscope and the saccadic fixator. Complicators such as plus and minus lenses, yolk prisms, and strobe lights may be employed to enhance concentration while performing the exercise.³

Instrumentation

The instruments used to assess and improve visual skills range from simple items, such as beanbags and flash cards, to complex (and expensive) devices. Your choices depend on the level of care you seek to provide.

For basic levels of sports vision assessment, every office should have a visual field analyzer. Although not a necessity, a corneal topographer can prove useful for difficult contact lens fits.

Color vision testing is also recommended for younger athletes who may not have undergone such testing before. Although it is true that if the patient has a color vision deficiency, it cannot be corrected, yet certain specialty lenses (such as the X-Chrom lens (ColorMax Technologies) are available that can improve some color vision defects. Ishihara pseudo-isochromatic plates and the Farnsworth D-15 tests are commonplace and easy to administer. If your interest lies in maximal measurement of an athlete’s color vision skill, invest in a Farnsworth-Munsell 100-hue test, a more elaborate, lengthier test.

Contrast sensitivity is an often overlooked visual skill that can have a significant impact on the athlete’s performance on the field. Very few athletes operate in a high-contrast (i.e. Snellen eye chart black-and-white) environment. An example of how contrast sensitivity affects athletic success: an outfielder who fields a pop-up fly ball. The white ball against a light blue sky presents a fairly low contrast environment. By evaluating that individual’s ability in this environment, you can devise a treatment plan to improve either the athlete’s ability or his compensatory skills. Several contrast sensitivity measuring instruments are available, such as the Optec 6500 Contrast Sensitivity View-in Tester (Stereo Optical), which is a relatively inexpensive, accurate way to measure this ability.

For more advanced levels of sports vision assessment and therapy, consider these instruments:

• Tachistoscope. This measures the speed at which visual information can be interpreted. Numbers, letters or images are flashed on a screen 10 feet away from the patient for 0.1 to 0.01 seconds. The patient must then say what he or she saw. A quarterback might be given 0.01 seconds to recognize different defensive formations.

• Various powers of prism/lens flippers. Keep on hand +/-2.00D lens flippers, 12 base-out prisms and three base-in prisms. Using the flippers, ask the patient to read a line of 20/40 letters alternating between the +2.00D and -2.00D lenses for a set period; repeat the process using the prisms. This technique lets you assess the athlete’s accommodative/vergence facility, a key factor in the ability to focus on, for example, the seams of a 90mph fastball.

• Marsden ball. This simple rubber baseball is suspended at chest-level from the ceiling with kite string. It is useful for improving eye-hand coordination and tracking skills.

• Brock strings/ropes. The string is three to five feet long with three small, multi-colored beads set equal distances apart. The athlete focuses on each one and names its color. This addresses spatial localization, focusing ability and vergence ability. Beads may also be moved closer to the nose to make the test more difficult.

The Brock rope, which is often used with basketball players, is 25 to 30 feet long. It hangs from the rim of the hoop while the athlete holds the other end to his or her nose while standing at the foul line. The training procedure is the same as with the Brock’s string and is done to enhance the same skill set.

• Bean bags and strobe lights. Begin with rudimentary tossing exercises, then introduce the strobe light in a dark room. The lower the frequency of the strobe light, the tougher the exercise. This is a relatively inexpensive way to improve the ability to track objects through space as well as enhancing visual attention and eye hand coordination. We have found this helpful for hockey goalies.

• Balance board/beam. This develops an awareness of the body’s location in space, and is ideal for wide receivers and running backs because of their need to remain in bounds when catching a ball thrown near the sideline or end zone. Athletes balance on the beam or board and are tossed bean bags. When proficient at that skill, they turn their backs and catch the bean bags over their shoulders.

• Lifesaver cards. These are five-by-seven-inch cards that can easily be used for home-based vision therapy. The cards have two columns of circles printed on them. At the bottom, the circles are closer together; at the top they are farthest apart. The objective is to overlap the circles. This develops vergence and focusing ability.

• Hand-held mirror. In this exercise, the patient holds the mirror directly in front of his or her face The mirror should be in contact with the face, with the edge running right down the middle of the forehead and nose.

Looking straight ahead, the patient will see the mirror with one eye while the other eye fixates on a target about five feet away. Based on how far the patient turns the mirror, he is able to increase or decrease the vergence demand on the visual system. This is a great way to work on vergence ability and eye pointing skills, as the test provides feedback on suppression tendencies and can enhance vergence skills.

• Hart charts. These two 11-by-11-inch charts are covered with random letters arranged in columns and rows, with a 20/40 acuity demand. The patient holds one chart; the other hangs on the wall. He calls out the first letter on the chart he holds, then the first letter on the wall chart, then the second letter on the near chart, and then the second letter on the far chart, repeating for one minute. Because this is a timed activity, the athlete is internally motivated to go faster and more accurately each time.

This is an easy and inexpensive way to work on focusing and saccadic eye movement skills. These skills are used in sports ranging from golf to auto racing; the need to change focus from near to far accurately and quickly is invaluable.

How to Market Your Sports Vision Services The easiest and least expensive way to promote your sports vision service is to do so internally. The telephone is a good place to start. Each time an employee answers the phone, she might say, “Thank you for calling Drs. Smith, Jones and Johnson, now offering sports vision enhancement.” Even better: “Thank you for calling. Please ask about our professional courtesy reduction for the month of October for new enrollees in our sports vision program.” Some additional internal marketing tips: • Dress the part. If you provide optometric services to a sports team, be it professional or high school, have your staff wear the team’s jerseys on the day of a big game. This can be a great conversation starter for discussing your sports vision service. • If you treat professional athletes, or even well known high school or college players, make them a part of your office décor. Signed programs, jerseys and photographs should adorn your practice walls. Realize that this requires a HIPAA compliance note. • Prominently display customized brochures in waiting rooms to advertise your services. If these are beyond your budget, the AOA Sports Vision Section (SVS) offers general-purpose brochures suitable to this end. External marketing techniques are more expensive, but they allow you to target a wider audience. Consider these options: • Have displays at ballparks or arenas. • Sponsor radio broadcasts of games and sports talk shows, sports segments of the evening news, or local sporting events. • Participate in volunteer screenings and/or eye care for local, professional, high school, or college teams. • Seek out sports-related speaking engagements. Although some options are pricey, our practice has arranged trade-for-service agreements with local minor league teams. In exchange for providing sports vision therapy for the players, we received an advertisement in the team’s yearly program, an advertisement on a section of the arena’s display boards, public announcement promotions made during every intermission and season tickets to give to patients interested in our sports vision service. In terms of billing, I recommend starting with smaller fees and working upwards. The important objective in the beginning should be improving your patients’ performance on the field, and then letting word-of-mouth be your best marketing device. This strategy is actually made easier when treating amateur, high school or college athletes, because room for visual improvement in these patients is much greater.

Going High Tech

Because the following instruments are more expensive, they are typically used on athletes who are intent on making a serious commitment to sports vision enhancement. These instruments include:

• Pegboard rotator. This is a motorized wheel with holes spaced every inch or so. The wheel has a rheostat that allows the therapist to change the revolutions per minute. Patients are asked to insert pegs into the holes to develop hand-eye coordination as well as pursuit eye movement skills.

• Wayne saccadic fixator. This large screen contains LED lights embedded in a plasma membrane. The athlete stands directly in front of the screen, and the lights randomly illuminate. The patient must reach out and touch the light as soon as it appears.

You can expand the range of this device with additions known as visual stick-ups, which you place along the outer edges of the screen.

The athlete stands farther back and shoots the stick-ups with an electronic pistol device, making this a useful exercise for target shooters.

• Various vectograms/tranaglyphs. These targets help athletes develop convergence and divergence abilities.

• Wayne Speed-Trac. This flexible 18-foot track consists of 32 sequential lights that simulate a moving target or “ball,” the speed of which you can pre-set in miles per hour. When the “ball” passes over home plate, the patient responds by swinging a bat or pressing a switch. The device can measure an anticipation error to within 0.001 seconds.

• HTS Computer Orthoptics. These are essentially computer-based vision therapy programs that work on everything from eye tracking to focusing and peripheral vision.

• Eye-hand, eye-foot reaction timer. The patient sits in front of two lights, spaced 24 inches apart, and places his hand or foot over the light that is on. When the other light illuminates, the patient releases the first switch and depresses the second, allowing the therapist to measure the athlete’s reaction time. This information is used as a benchmark for future reference when attempting to quantify an athlete’s improvement.

Customize Your Approach

Each vision program should be customized to the athlete’s sport. For example, a darts player will not need to concentrate heavily on dynamic visual acuity or peripheral vision because he or she is not dealing with images moving at a high rate of speed on a large playing field. This athlete will be more interested in static visual acuity and depth perception. A hockey goalie, however, will rely on very keen peripheral vision and dynamic visual acuity.

All athletes should be tested for overall vision, but concentrate your efforts in the areas in which they will have the greatest impact.

Vision Correction

Generally speaking, fitting athletes with contact lenses is preferable to spectacles, due to the known visual advantages offered by contact lenses, such as improved peripheral awareness and better contrast sensitivity.

In sports such as squash, racquetball, handball and tennis, however, athletes must be encouraged to wear protective goggles that offer impact resistant lenses. Even athletes with very high reaction response times are at risk of being hit in the eye at some point while engaged in these sports. Protective eyewear offers excellent vision under these circumstances, as long as the prescription is not in the high myopic or hyperopic range. (Peripheral distortion becomes an issue at higher ranges.) High myopes and hyperopes should be fit with contact lenses and wear plano protective eyewear in these sports.

Although most swimmers that require corrective lenses wear contact lenses with plano swim goggles, some swimmers are more comfortable in prescription goggles rather than contacts. Keeping the chlorine water off their corneas while underwater provides clearer vision and a better safety profile. If at all possible, fit swimmers who prefer contact lenses in daily disposable contact lenses in order to decrease the opportunity for infection.

Positional stability of all contact lenses (but especially toric contacts) is important for sports that require rapid eye movements in various fields of gaze. A delay in contact lens reorientation may negatively affect vision performance, so I tend to fit larger diameter lenses.

I generally try to fit athletes in disposable lenses (single-use lenses if possible). Single-use lenses are especially suited for patients who hunt, camp or fish, and who do not wish to pack lens cases and care products. These lenses also are ideal for baseball players who play in a dusty, dirty environment during the spring and summer months when allergens are prevalent.

Keep an eye out for technological innovations. For example, last year, the FDA approved the Nike MaxSight sport-tinted contact lenses (Bausch & Lomb) for use in athletic settings. These lenses come in two tints: gray-green for extremely bright conditions to enhance visual information in the green range (e.g., golf) and amber for fast ball sports such as baseball, soccer and tennis.

Nike MaxSight sport-tinted contact lenses (Bausch & Lomb) come in an amber tint for fast ball sports, such as baseball, soccer and tennis. A gray-green tint for extremely bright conditions is also available to enhance visual information in the green range (e.g., golf).

Weather and Environment

Factors influencing the choice of contact lenses include wind conditions, dirt and dust, humidity, altitude, temperature and exposure to ultraviolet (UV) radiation. Lens choice may be affected by water content and Dk values when high altitude and low humidity are part of the environment. For example, the low humidity of an ice hockey rink will cause contact lenses to dry out very quickly, so these patients may require a lens that has lower water content. In an environment in which dirt and debris are prevalent, a contact lens with a larger diameter can help prevent foreign matter from getting between the lens and cornea.

Ocular damage from sunlight is a significant risk for patients who ski. Spending all day in the sun on the slopes without protection—the snow reflects up to 85% of the UV radiation that shines onto it—can result in “snow blindness,” or exposure keratitis. Skiers require 100% UV protection in the form of sunglasses or tinted ski goggles.

Because of the various environmental factors faced by athletes, be sure to educate patients about the importance of hygiene. Baseball, football and soccer players often have dirt on their hands; instruct them to use alcohol-based hand cleaners and then wait 15-20 seconds before repositioning or changing their contact lenses.

Swimmers should remove their contacts upon leaving the water and wait at least 30 minutes before inserting new lenses, thus allowing the cornea to recover from the hostile chlorine environment. One precaution: Warn patients of lens adhesion after swimming in pools and fresh water and to wait 30 minutes after swimming to remove lenses in order to prevent epithelial damage.

Among spectacle wearers, tints are often popular with hunters, target shooters and fishermen. They act as filters to reduce the overall amount of visual light and in some cases screen out specific wavelengths. Reducing overall light limits eye fatigue and can improve visual acuity.

Some tints can enhance contrast sensitivity, as well. For example, I’ve prescribed yellow, amber and vermillion tints that have been successful for shooters.

Polarized lenses are designed to block the glare from reflective surfaces such as water. These lenses are a must for fishermen, because they enhance their ability to see down into the first few feet of water. Polarized lenses can also be effective in driving sports.

Emergency Treatment

There are more than 40,000 eye injuries every year in the United States—many of which are sports-related, and sports injuries are a common cause of severe vision loss.⁴ The sports that most commonly cause eye injuries, in order of decreasing frequency, are basketball, water sports, baseball, and racquet sports.⁵ Sports-related eye injuries are blunt, penetrating, and radiation injuries.

In one study, modern sports were responsible for 8.3% of the 288 total sports eye injuries reported.⁶ Squash (29.2%) was the most common cause, followed by paintball (20.8%) and motocross (16.6%). The most common diagnosis during the follow-up period was retinal breaks (20%). Some 18 (75%) patients sustained a severe injury. The final visual acuity remained <20/100 in two paintball players.

A comprehensive discussion of emergency sports treatment is beyond the scope of this article, but if you are interested providing sports vision care to amateur or professional teams, you need to be be prepared to offer these services. In my contract with a professional hockey team, one of our optometrists was always readily available for home games, and on more than one occasion, we brought an injured player into our office for emergency treatment.

 

Athletic patients have special visual needs. By taking the time and effort to meet them, you can grow your practice, increase patients’ enjoyment of their sport and have a refreshing change of pace. ■

Dr. Hefner is in private practice in Topeka, Kan., and has provided sports vision care for the St. Louis Rams, Topeka Knights and Topeka ScareCrows.