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Effectiveness of eye armor during blast loading

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Ocular trauma is one of the most common types of combat injuries resulting from the interaction of military personnel with improvised explosive devices. Ocular blast injury mechanisms are complex, and trauma may occur through various injury mechanisms. However, primary blast injuries (PBI) are an important cause of ocular trauma that may go unnoticed and result in significant damage to internal ocular tissues and visual impairment. Further, the effectiveness of commonly employed eye armor, designed for ballistic and laser protection, in lessening the severity of adverse blast overpressures (BOP) is unknown. In this paper, we employed a three-dimensional (3D) fluid–structure interaction computational model for assessing effectiveness of the eye armor during blast loading on human eyes and validated results against free field blast measurements by Bentz and Grimm (2013). Numerical simulations show that the blast waves focused on the ocular region because of reflections from surrounding facial features and resulted in considerable increase in BOP. We evaluated the effectiveness of spectacles and goggles in mitigating the pressure loading using the computational model. Our results corroborate experimental measurements showing that the goggles were more effective than spectacles in mitigating BOP loading on the eye. Numerical results confirmed that the goggles significantly reduced blast wave penetration in the space between the armor and the eyes and provided larger clearance space for blast wave expansion after penetration than the spectacles. The spectacles as well as the goggles were more effective in reducing reflected BOP at higher charge mass because of the larger decrease in dynamic pressures after the impact. The goggles provided greater benefit of reducing the peak pressure than the spectacles for lower charge mass. However, the goggles resulted in moderate, sustained elevated pressure loading on the eye, that became 50–100 % larger than the pressure loading experienced by the unprotected eye after 0.2 ms of impact of blast wave, for lower as well as higher charge mass. The present model provides fundamental insights of flow and pressure fields in the ocular region, which helps to explain the effectiveness of the eye armor. Since the measurements of these fields are not trivial, the computational model aids in better understanding of development of PBI.

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  1. FOCUS headforms are designed by Humanetics Innovative Solutions, in collaboration with the Virginia Tech-Wake Forest Center for Injury Biomechanics and the US Army Research Laboratory. (

  2. Zygote Media Group, Inc is a developer company for computer-generated 3D graphical software and specialized in the enhanced visualization of the human anatomy (

    Fig. 2
    figure 2

    Skin model used in this study (a) showing the location of the three virtual probes placed in the ocular region and the position and fitting of models representing (b) spectacles and (c) goggles. The insets of (b) and (c) represent standard-issue spectacles and goggles, designed for ballistic protection in military operations, on which we based our respective computational models. Note that in the model representing goggles, we omitted retainer straps, since the goggles were assumed to fit securely on the face and were treated as a rigid object

  3. Blender is a free, open-source modeling software, developed by The Blender Foundation. (

  4. Computer animation for flow and pressure field for unprotected eye in sagittal plane (supplement movie 1).

    Fig. 4
    figure 4

    Results for 6.4-kg TNT blast tests with a bare headforms and protected headforms employing b spectacles and c goggles, indicating pressure fields and velocity vectors around the eye, at respective instants of maximum reflected BOP, in sagittal planes. Velocity vectors are shown at every 15th grid point

  5. Computer animation for flow and pressure field for unprotected eye in transverse plane (supplement movie 2).

  6. Computer animation for flow and pressure field for eye protected with spectacles in sagittal plane (supplement movie 3).

  7. Computer animation for flow and pressure field for eye protected with spectacles in transverse plane (supplement movie 4).

  8. Computer animation for flow and pressure field for eye protected with goggles in sagittal plane (supplement movie 5).

  9. Computer animation for flow and pressure field for eye protected with goggles in transverse plane (supplement movie 6).


  • Alphonse VD, Kemper AR, Strom BT, Beeman SM, Duma SM (2012) Mechanisms of eye injuries from fireworks. JAMA 308(1):33–34

    Article  Google Scholar 

  • Ari AB (2006) Eye injuries on the battlefields of Iraq and Afghanistan: public health implications. Optometry 77:329–339

    Article  Google Scholar 

  • Bailoor S, Soti AK, Bhardwaj R, Nguyen TD (2013) Effectiveness of eye armor during blast loading. In: Proceedings of the ASME 2013 summer bioengineering conference, Sunriver, OR, USA

  • Bentz V, Grimm G (2013) Joint live fire (JLF) final report for assessment of ocular pressure as a result of blast for protected and unprotected eyes (Report number JLF-TR-13-01) U.S. Army Aberdeen Test Center, Aberdeen Proving Ground, MD

  • Bhardwaj R, Ziegler K, Seo JH, Ramesh KT, Nguyen TD (2014) A computational model of blast loading on the human eye. Biomech Model Mechanobiol 13(1):123–140. doi:10.1007/s10237-013-0490-3

  • Bricker-Anthony C, Hines-Beard J, Rex TS (2014) Molecular changes and vision loss in a mouse model of closed-globe blast trauma. Invest Ophthalmol Vis Sci 55(8):4853–4862. doi:10.1167/iovs.14-14353

    Article  Google Scholar 

  • Chalioulias K, Sim KT, Scott R (2007) Retinal sequelae of primary ocular blast injuries. J R Army Med Corps 153(2):124–125

    Article  Google Scholar 

  • Densmore JM, Homan BE, Biss MM, McNesby KL (2011) High-speed two-camera imaging pyrometer for mapping fireball temperatures. Appl Opt 50(33):6267–6271. doi:10.1364/AO.50.006267

    Article  Google Scholar 

  • Duma S, Kennedy E (2011) Final report: eye injury risk functions for human and FOCUS eyes: hyphema, lens dislocation, and retinal damage. Technical report, U.S. Army Medical Research and Material Command Fort Detrick, Maryland. Accessed 21 Feb 2015

  • Esparza E (1992) Spherical equivalency of cylindrical charges in free-air. 25th Department of Defense Explosives Safety Seminar, 18–20 August 1992. Available at

  • Esposito L, Clemente C, Bonora N, Rossi T (2013) Modelling human eye under blast loading. Computer Methods in Biomechanics and Biomedical Engineering. doi:10.1080/10255842.2013.779684

  • Goroshin S, Frost DL, Levine J, Yoshinaka A, Zhang F (2006) Optical pyrometry of fireballs of metalized explosives. Propellants Explos Pyrotech 31:169–181. doi:10.1002/prep.200600024

    Article  Google Scholar 

  • Hamit HF (1973) Primary blast injuries. Ind Med Surg 43(2):14–21

    Google Scholar 

  • Hines-Beard J, Marchetta J, Gordon S, Chaum E, Geisert EE, Rex TS (2012) A mouse model of ocular blast injury that induces closed globe anterior and posterior pole damage. Exp Eye Res 99(1): 63–70

    Article  Google Scholar 

  • Kingery CN, Bulmash G (1984) Airblast parameters from TNT spherical air burst and hemispherical surface burst. Defence Tech Rep Report ARBL-TR-02555, U.S. Army BRL, Aberdeen Proving Ground, MD

  • La Piana FG, Ward TP (1999) The development of eye armor for the American infantryman. Ophthalmol Clin N Am 12(3):421–434

    Article  Google Scholar 

  • Lele S (1992) Compact finite difference schemes with spectral-like resolution. J Comput Phys 103:16

    Article  MATH  MathSciNet  Google Scholar 

  • Mittal R, Dong H, Bozkurttas M, Najjar FM, Vargas A, von Loebbecke A (2008) A versatile sharp interface immersed boundary method for incompressible flows with complex boundaries. J Comput Phys 227(10):4825–4852

    Article  MATH  MathSciNet  Google Scholar 

  • Rossi T, Boccassini B, Esposito L, Clemente C, Iossa M, Placentino L, Bonora N (2012) Primary blast injury to the eye and orbit: finite element modeling. Invest Ophthalmol Vis Sci 53:8057–8066

    Article  Google Scholar 

  • Sherwood D, Sponsel WE, Lund BJ, Gray W, Watson R, Groth SL, Thoe K, Glickman RD, Reilly MA (2014) Anatomical manifestations of primary blast ocular trauma observed in a postmortem porcine model. Invest Ophthalmol Vis Sci 55:1124–1132. doi:10.1167/iovs.13-13295

    Article  Google Scholar 

  • Slotnick JA (2010) Explosive threats and target hardening understanding explosive forces, it’s impact on infrastructure and the human body. In: Fourth international symposium on tunnel safety and security, Frankfurt am Main, Germany, 17–19 March 2010

  • Stitzel JD, Weaver AA (2012) Computational simulations of ocular blast loading and prediction of eye injury risk. ASME SBC 2012: SBC2012-80792

  • Weaver AA, Loftis KL, Tan JC, Duma SM, Stitzel JD (2010) CT based three-dimensional measurement of orbit and eye anthropometry. Invest Ophthalmol Vis Sci 51(10):4892–7

    Article  Google Scholar 

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This research was supported by US Army Medical Research, Vision Research Program under grant number W81XWH-10-1-0766. Meshes of the head and eye armor were provided by WMRD, US Army Research Laboratory, Aberdeen MD. We thank Professor R. Mittal and Dr. Adam Fournier for helpful discussions. R.B. gratefully acknowledges financial support from Department of Science and Technology, New Delhi, through fast track scheme for young scientists.

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Correspondence to Rajneesh Bhardwaj.

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Bailoor, S., Bhardwaj, R. & Nguyen, T.D. Effectiveness of eye armor during blast loading. Biomech Model Mechanobiol 14, 1227–1237 (2015).

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