Background: Baseball is the leading cause of sports-related eye injuries in
young persons. It is known that softer baseballs reduce the potential for
brain and cardiac injury, but it has been speculated that softer baseballs
may increase eye injuries by intruding more into the orbit. It also has bee
n claimed that softer baseballs would change the "feel" of the game.
Objectives: To determine the orbital intrusion and eve injury potential of
baseballs of varying hardness, and whether a player can feel the difference
between these different baseballs.
Main Outcome Measures: Orbital force and penetration of baseballs of variou
s hardness into an artificial orbit. Ability of subjects of varying age and
baseball experience to determine the hardness of baseballs.
Results: The peak orbital force and force onset rate from softer baseballs,
at all impact velocities, were less than the force and force onset rate fr
om baseballs that had hardness equal to, or greater than, major league base
balls. The softest (10% of major league hardness) baseballs intruded into t
he orbit significantly more than balls that were 15% of major league hardne
ss or harder. Children younger than 14 years could not differentiate balls
15% of major league hardness or harder, and adults could not differentiate
20% of major league hardness or harder from each other or from major league
balls.
Conclusion: The potential for injury to the unprotected eye from soft baseb
alls is significant, hut not greater than that from a major league baseball
. Baseballs that are 15% to 20% of major league ball hardness are recommend
ed for youth baseball because these balls feel like major league balls, red
uce the potential for brain injury and commotio cordis, cause less pain on
impact, and do not increase the potential for eye injury to the unprotected
player. Eye injuries in youth baseball could be minimized by the use of pr
otective eyewear that conforms to the standard specifications of the Americ
an Society of Testing and Materials (Philadelphia, Pa), standards F910 (for
batters and baserunners) and F803 (for fielders).