Evaluation of the protective efficiency of polycarbonate goggles against firecracker-related ocular injuries

Dear Editor, The festival of Diwali is celebrated with fervor and joy all over the country. Lighting of lamps and firecrackers is an inherent part of the festivities. Unlike other parts of the world where igniting fireworks is regulated and reserved, India has the unique tradition of each home or individual lighting crackers separately. Every year, firecrackers are responsible for ophthalmic and non-ophthalmic injuries such as singeing of lashes and eyebrows, lacerations, and burns in the periorbital area. Burnt flying projectiles hitting the eye may result in both open and closed globe ocular injuries, leading to vision loss and blindness.[1,2] Though we understand that it may be difficult to restrict the use of firecrackers, we conducted an experiment to evaluate whether the likelihood of high-velocity burning projectiles striking the eyes could be reduced, thereby preventing consequent ocular injuries, particularly among children and adolescents. It is known that industrial workers routinely use polycarbonate glasses while performing tasks like welding, grinding, chiseling, etc., to prevent ocular injuries. We evaluated, using a mannequin head with enucleated goat eyes in a simulated environment, whether industrial polycarbonate glasses could block the impact of firecracker projectiles. To simulate a real-life scenario, a mannequin head with the orbital area cut out was fitted with a pair of enucleated goat eyes [Fig. 1a]. Protective glasses (3M polycarbonate 1611 safety goggles) were then put on the mannequin [Fig. 1a]. A commonly used explosive firecracker (bullet bomb) with 30 small pebbles placed within a 30 cm circumference (to simulate surrounding debris) was ignited at a distance of half a meter from the mannequin. A total of 10 blasts were done. On subsequent examination of the mannequin, it was observed that none of the blasts had penetrated through the safety goggles, and no damage to the goat eyes was observed.Figure 1: (a) Photograph showing a mannequin head with orbital area cut out and fitted with enucleated goat eyes, along with 3M polycarbonate 1611 safety goggles completely covering eyes and periorbital area. (b) Photograph showing significant damage to the goat eyes due to high-velocity particles and debris following a firecracker explosionIn the next part of the experiment, the protective glasses were removed, and the same process was repeated. In this case, it was found that the goat eyes were significantly damaged due to the particles and surrounding debris that had clung to the ocular surface [Fig. 1b]. To further evaluate whether the protective glasses could protect the eyes from high-velocity firework pellets or debris, we used a nitrogen piston break-barrel air gun (maximum velocity 860 fps and power of 20 J) using 0.177 mm sharp head pellets to fire at the mannequin with protective glasses on from 5 meters. Air gun pellets are known to cause non-lethal injuries and have the potential to penetrate human eyes, as described in the past.[3,4] None of the air gun pellets could penetrate through the glasses, leaving only pits on the surface [Fig. 2]. The glasses showed pitting but did not allow penetration, hence providing effective protection to the goat eyes.Figure 2: Photograph showing pitting on the surface of polycarbonate glass by air gun pellets. However, there was no full-thickness penetrationHence, we conjecture that industrial safety glasses can provide effective protection to the eyes from flying projectiles coming out of bursting firecrackers, and their use may prevent ocular injuries. The limitation of this experiment is that we could not evaluate if there was any concussive damage due to the shockwave of an explosion and if the glasses offered any protection against it, as even in freshly sacrificed goats, the corneas turned white, preventing a view of the fundus. Despite this limitation, we believe that this experiment does simulate a real-life environment and paves the way for further studies in this regard. Financial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.