Sports injuries account for around 40,000 eye injuries within the United States, with a significant proportion of them occurring in individuals under the age of 30. Children are probably the most susceptible group for ocular injuries due to their underdeveloped sense of depth perception and slow hand and eye coordination. A child may misjudge the speed and placement of a ball, miss it, and be struck in the face, resulting in an injury. The sports in which eye injuries are the most common every year are basketball, baseball, and racquet sports.
Eye injuries can vary from minor bumps and scrapes to major traumas that result in loss of vision that can be temporary or permanent. The following are common eye injuries that can result from recreational activities.
Corneal abrasion – A corneal abrasion is classified as a scrape of the clear portion of the surface of the eye, and can be extremely painful. Additional symptoms are a foreign body sensation, tearing, blurred vision or vision loss, photophobia and squinting.
Traumatic iritis – Traumatic iritis commonly occurs when blunt force trauma to the eye causes iritic bruising, iris sphincter tears, or, more seriously, iriodialysis, a condition in which the iris pulls away from the wall of the eye. Because the injury and resulting inflammation may prevent the iris from opening and closing properly, photophobia may result. Further symptoms include redness, acute pain, blurry vision and glare.
Hyphemas – Hyphemas are the result of blood in the anterior chamber after blunt force trauma to the eye. The blood can either present itself as a reddish tinge along the posterior surface of the cornea or as a pool of blood. Although it normally rectifies itself in time, it can lead to a complete or partial block in vision. If the Hyphema takes an abnormally long time to heal, iron deposits on the cornea or a change in eye color may occur. An increase in ocular pressure is also not uncommon if the intra-ocular drainage system is blocked by blood.
Orbital Blowout Fractures – An orbital blowout fracture occurs when a blunt object strikes the eyeball itself, resulting in the compression of the globe. This sudden compression causes the globe to displace itself vertically which can result in a fracture of one or more of the seven bones that make up the orbital cavity. Although the fracture may occur anywhere, it is typically seen along the orbital floor in the maxillary bone. If the intra-orbital pressure is immense, the orbital contents may go into the fracture sight and possibly into the sinus cavity.
Symptoms can range from asymptomatic, to facial pain and tenderness, blurred vision, bleeding, eye redness, swelling of the lids, ocular pain, drooping eyelid, and loss of motility resulting in double vision. The motility loss can be the consequence of nerve and muscle being pinched either from the bone itself, a hemorrhage, or edema. Typically, the patient is unable to rotate the globe upwards because the inferior rectus muscle becomes trapped in the bone fragments.
Lacerations – Lacerations, or cuts, can occur to the conjunctiva, sclera or cornea.
Foreign Bodies – Foreign bodies may present with different symptoms based on where the foreign body is in relation to the eye. Corneal foreign bodies may present with tearing, blurred vision and photophobia. The object itself may be seen in the cornea. If the object is metal, a rust stain can occur. Intraorbital foreign bodies may be asymptomatic, especially at first, but decreased vision, pain and double vision may occur hours or days after the injury. Intraocular foreign bodies may initially have no symptoms as well, but eye pain and decreased vision may present itself later.
Although these eye injuries can be devastating, this is not always the case and luckily, 90% of all eye injuries are preventable according to Prevent Blindness America. One of the easiest and most efficient ways to prevent eye injuries is through the use of sports eyewear.
Making the Most of Impact Resistance
The first step in providing the patient with superior sports glasses is picking the proper lens. Polycarbonate is the lens material of choice for sports eyewear, due to the inherent impact resistance of the material. Polycarbonate is still the gold standard for impact resistance.
Polycarbonate has been used in eyewear since 1979, although not commonly until the mid 1980’s. A strong, lightweight and highly durable lens, polycarbonate has a large market share within the United States for impact resistant eyewear. It does have some major drawbacks, however. Polycarbonate, with an ABBE value of 30, has the lowest ABBE value of any lens on the market. In addition, polycarbonate is very difficult to tint because of the hardness of the scratch coat that is needed to protect the soft, flexible, polycarbonate material. When tint on a sports lens is desired, if ordering polycarbonate, be sure to specify a tintable scratch resistant coating and use lower temperatures when tinting.
Trivex® is the latest advancement in impact resistant lens materials. Developed by PPG Industries in 2001 for the United States military, Trivex combines the some of the impact resistance and benefits of polycarbonate, with a higher ABBE value of 43. Although Trivex is more expensive than polycarbonate, it can be easily tinted in a wide range of colors. Keep in mind that Trivex absorbs tint very quickly so the ECP should tint the lens at a lower temperature than standard and should check the color frequently.
Both materials are available in polarized, single vision, lined multifocal and progressive lens styles.
Enhancing the Lens through Color
Although there are many different color combinations and tinting densities to choose from, some common colors that work well with athletic activities are:
Yellow and Orange: These colors heighten contrast between objects and blue or green backgrounds. Sometimes marketed as “blue blockers,” yellow and orange tints are good for hazy, foggy or overcast conditions. Not an appropriate color for an activity that depends on accurate color perception, it is an excellent choice for low light and indoor activities.
A word of caution, yellow and orange can cause discomfort to the eyes when used in extreme bright light conditions.
Rose and Red: Although these colors heighten contrast in partly cloudy and sunny conditions, they may cause significant color imbalances. The main benefit to these colors is that they allow the patients’ eyes to adjust quickly between alternating light conditions.
Purple: Commonly used as a fashion tint, dark purple can shade the eye while maintaining natural color perception.
Dark Amber, Brown, and Copper: These colors help reduce glare and perform best in hazy sunshine. They are especially advantageous in improving contrast on grass and against blue skies; as well as activities where glare and depth perception can be a deciding factor.
Green/Gray: A mild, contrast enhancing tint, green/gray is generally used to reduce eyestrain under bright lighting conditions. As soothing tints, they offer the best contrast and visual acuity of all tints due to the fact that the visible spectrum will transmit through the lenses in the exact same manner that it does in the human eye.
When participating in the activities in which eye injuries are likely to occur, certain colors work better than others:
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Hunting/Shooting- yellow/orange, rose/red, and dark amber, brown and copper, purple
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Water sports- yellow/orange, rose/red, dark amber, brown and copper
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Golf- dark amber, brown and copper, green/gray
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Baseball and racquet sports- dark amber, brown and copper, green
Deciding to go Polarized
Tints, although an effective option in sports eyewear, are not as efficient as polarized lenses. Tinting only makes the lens darker, thereby blocking the amount of usable light entering the eye while allowing glare to pass through. Polarization on the other hand, acts as a filter. Polarization is a film that is inside the lens and acts like a Venetian blind, blocking reflected light that causes harmful glare. As a result, glare is eliminated and the wearer will experience increased comfort, visual acuity and contrast.
Dark Gray- 25% light transmission; truest color recognition and is ideal for bright sunny days and high glare activities such as deep water fishing and driving
Light Gray- 55% light transmission; ideal for being used with tints to create a custom colored polarized lens
Dark Brown- 25% light transmission; as a semi-blue blocker, it is ideal for improved contrast, visual acuity and depth perception, and is useful in activities such as driving and shallow water fishing
Light Brown- 45% light transmission; ideal for being used with tints to create a custom colored polarized lens
Melanin- 25% light transmission; a relatively new lens to the market, it contains the pigment that normally occurs in the body and is ideal for anyone with macular degeneration and works well in bright conditions and activities in which the light varies such as golfing
Red- 55% light transmission; a high contrast lens that is ideal for low light fishing and as a shooting lens in bright light
Orange- 50% light transmission; blocks blue light, increases contrast and is most commonly used for clay target shooting (depending on the skeet color), biking, and skiing
Green- 60% light transmission; true color balanced lens that works well in varying light conditions such as golf and tennis
Violet- 55% light transmission; increases contrast and darkens certain backgrounds so it works well with shooting in average to bright, golfing and for winter sports
Yellow- 80% light transmission; eliminates blue light which increases contrast significantly. The increased contrast makes the individual objects truly stand out from their background
Polarized polycarbonate lenses are available from Seiko, Younger Optics, Essilor, Hoya, and Shamir to name a few. The first Trivex polarized lens is the NXT Polarized Sunless by PPG. By confining the polarized film to the 0.9mm of the lens surface, PPG provides a lens that retains its color over time and remains uniform regardless of thickness and surfacing processes.
Sports Frame
Effective sports frames are lightweight and customarily made out of nylon, Kevlar or a nylon/polycarbonate blend to provide durability. Large, rubber nose pads evenly disperse weight to provide comfort and decrease slipping. The frame should be snug and form fitting to diffuse the impact of a blow over a larger area, away from the eyeball. A wrap fit is also desirable with a strap instead of traditional temples.
All sport frames that the ECP recommends should be verified that they are ASTM approved for that sport and that the frame literature indicates that the frame has passed the F803.88 standard for sports protection.
Conclusion
Eye injuries can not only occur due to an accident, but through professional negligence by the ECP as well. Ocular injuries can be incredibly painful as well and lead to short term or long term vision loss. Luckily, prevention is key with eye injuries. By providing the best in sports eyewear, a majority of injuries can be prevented. Ultimately the patient wins and the ECP has significant intrinsic pride in providing the best care for each of their patients.
