Ocular Injuries Caused by Airsoft Guns

In the past 2 years, we observed in our outpatient clinic an escalating number of ocular injuries caused by "airsoft" or "softgun" toy weapons. In contrast to the conspicuous hazard of classical air guns (BB guns), this new kind of toy weapon implies a dangerously misleading harmlessness, both because of the airsoft name and because the gun is made of plastic. These toy guns have gained popularity among youngsters since they are relatively cheap, can be purchased without age restrictions, and look real.

To our knowledge, no reports have previously been published on eye injuries caused by these guns. The purpose of this study is to illustrate their potential ocular hazards and to propose preventive measures.

Airsoft guns consist of a plastic pistol that shoots hard plastic bullets with a diameter of 6.0 mm (Figure 1). These bullets are available in different weights (0.12, 0.2, and 0.25 g), all of which are much lighter than the lead bullets used in BB guns (0.52-1.6 g). The guns use the direct force of a spring coil or compressed air to fire bullets. In an independent ballistic investigation,¹ the calculated energy for bullets weighing 0.2 and 0.12 g was 0.363 and 0.347 J, respectively. This energy results in velocities of 61.5 and 74.9 m/s, respectively, and in-flight ranges of 30 to 50 m, respectively. The bullets are made of a very hard and noncompressible plastic material and thus, do not absorb energy. They can cause injuries, even when they ricochet from rigid surfaces. In comparison, BB gun bullets reach speeds of 100 to 200 m/s and a flight range of 100 to 150 m.

Between October 1996 and July 1998, 9 male patients were treated, 8 at the eye clinic of the University of Bern and 1 at the eye clinic of the University of Basel, Switzerland, for ocular injuries caused by airsoft bullets. After reviewing the medical charts, patients were scheduled for an additional eye examination. Mean follow-up was 8.8 months (range, 0.5-24 months). Mean ± SD age was 13.9±2.3 years (range, 11-17 years). All patients were male and only 1 eye was affected. In 2 cases, bullets ricocheted from a wall into the eye; in the other 7 cases, the eye was hit directly.

A summary of the results is given in Table 1. Initial visual acuity was counting fingers or light perception in 3 patients, between 20/100 and 20/25 in 4, and 20/20 in 2. Final visual acuity was 20/20 in 8 patients and 20/25 in 1.

In 6 patients, corneal erosion and stromal edema matching the bullet size (Figure 2) were seen. Cataract development was observed in 3 patients; 2 showed a transient increase of intraocular pressure due to hemorrhagic glaucoma. Chamber angle recession was present in 2 patients, iridodialysis in another.

Injuries of the posterior segment were observed in 5 eyes. In 1 of these eyes, there was total hyphema with subsequent hematocornea and dense vitreous hemorrhage. A pars plana vitrectomy, combined with phacoemulsification and a posterior chamber lens implantation, was performed. Initial visual acuity was light perception; final visual acuity of 20/25 was attained 3 months after injury.

Another case of posterior segment injury showed a peripheral choroidal rupture but only a small vitreous hemorrhage. Initial and final visual acuity was 20/20. The area of choroidal rupture remained unchanged during the 14-month follow-up.

Previous to our series, ocular injuries due to air guns have been reported only in the context of BB guns,² including penetrating globe injuries or retrobulbar optic nerve trauma leading to severe visual impairment or loss of the eye.^3,4 Other severe nonocular injuries have been observed, some of which have led to death.⁵ This severity is due to the much higher energy of BB bullets (0.072 J/mm²)—which exceedes that necessary for scleral penetration (0.06 J/mm²)⁶—than the considerably lower energy density (0.01 J/mm²) of airsoft bullets.¹

In our series, airsoft bullet injuries ranged from light contusions to severe sight-threatening closed-globe injuries. These are less severe than with BB guns, possibly because airsoft bullets are larger and have lower energy. The worst injury in our series was a total hyphema combined with traumatic cataract, and a dense vitreous hemorrhage.

However, in contrast to BB guns, airsoft guns are easily available and their sale is not restricted by age. Airsoft guns were designed as a toy and are still marketed as a toy. The innocent name and misleading marketing contribute to the danger of airsoft guns. Safety goggles are not supplied with the guns, but are at least recommended in product manuals. In all cases, goggles could have prevented injuries.

Airsoft guns have the additional liability that it is very easy to replace the plastic bullets with much heavier steel or lead bullets, which develop the same energy at a distance of 40 to 50 m that plastic bullets develop at 10 m.⁷

Airsoft guns should not be considered to be toys but rather, as weapons with the potential of causing severe eye injuries. Globe ruptures or penetrating traumas were not observed in our series, but 1 injury was severe enough to require intraocular surgery. In the United States, some states recently passed legislations limiting the import and sale of these weapons.

All patients with eye injuries due to airsoft guns should be referred to an ophthalmologist for further evaluation. Safety goggles should be included with the guns and wearing them should be mandatory while playing. Age or sale restrictions should also be considered.

Corresponding author: Beatrice E. Frueh, MD, Department of Ophthalmology, University Hospital, Inselspital, Freiburgstrasse, CH-3010 Bern, Switzerland (e-mail: beatrice.frueh.epstein@insel.ch).