Laser Tissue Interactions

What is the effect of lasers on the eye?

Laser eye injuries are the most commonly reported injury associated with laser use (Kim & Ra, 2019). Consistent with the uptake of more laser devices and procedures, there has been an upward trend to reported laser eye injuries over recent times. (Lee et al., 2024; Qutob et al., 2019; Tran et al., 2020). Laser eye injuries are occurring in the home, in cosmetic clinics and in medical settings. Eye injuries from lasers range from mild ocular discomfort to permanent central vision loss and reduction in quality of life (Lee et al., 2024). 

Laser tissue damage in the eye may arise from photothermal, photochemical and photodisruptive mechanisms. As the name suggests, the photothermal effect occurs when laser energy is absorbed into eye tissue resulting in a temperature rise. A rise in temperature essentially burns the effected tissue which may lead to permanent damage (Wong et al., 2020). Photochemical affects occur when long pulses of low power laser energy results in a series of chemical reactions in the involved tissue (Wong et al., 2020). Photodisruptive affects occur when laser energy is absorbed rapidly in a short pulse stripping electrons and destroying the impacted tissue(Wong et al., 2020).

The structure of the eye effected depends on the type of laser used (Wong et al., 2020). High powered lasers may impact multiple structures of the eye simultaneously (Lin & Dong-Kan, 2026). The retina is the most common structure of the eye damaged from laser use (Kim & Ra, 2019). This is due to several reasons, firstly the eye is designed to amplify and focus light on the retina. When the eye focuses a laser beam on the retina it results of an optical gain of 100,000 therefore significantly increasing the irradiance of the laser beam (Barat, 2022). Secondly, whilst most of the eye is transparent the retina and choroid are pigmented allowing it to readily absorb light energy. Although this helps us see, it is problematic in the context of laser exposure as this results in absorption of laser into the retinal tissue.

How do lasers impact the skin?

Intentional or unintentional laser exposure to the skin may result in a series of complications including burns, scarring and permanent pigmentary changes. In a cosmetic or dermatological setting, the inappropriate device or mismatched parameters increases the risk of complications (Nguyen et al., 2026). It is also important to be aware of variables beyond operator error that increase the risk of skin complications secondary to laser exposure. Certain medications can cause an increased photosensitivity to the skin and these are known as photosensitisers (Nguyen et al., 2026). An example of a photosensitiser is doxycycline which is a common antibiotic (Barat & Institute of Physics, 2022). Among patient-related factors, the Fitzpatrick skin type is the most critical. Individuals with greater skin pigmentation are at a higher risk of complications because a higher level of melanin in the skin absorbs laser energy (Nguyen et al., 2026). Underlying bacterial, viral, or fungal infections can be exacerbated when treated with lasers; Herpes simplex reactivation is also a well known complication from laser treatments (Nguyen et al., 2026).

Author: Oliver Ried, B. Vis Sci, M. Optom, Grad Cert OHS.

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Lin, B., & Dong-Kan, L. (2026). Full-thickness macular penetration by welding laser injury. Eye (London). https://doi.org/10.1038/s41433-026-04702-y

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Qutob, S. S., Feder, K. P., O'Brien, M., Marro, L., McNamee, J. P., & Michaud, D. S. (2019). Survey of reported eye injuries from handheld laser devices in Canada. Canadian Journal of Ophthalmology, 54(5), 548–555. https://doi.org/https://doi.org/10.1016/j.jcjo.2019.02.001

Tran, K., Wang, D., Scharf, J., Sadda, S., & Sarraf, D. (2020). Inner choroidal ischaemia and CNV due to handheld laser-induced maculopathy: a case report and review. Eye, 34(11), 1958–1965. https://doi.org/10.1038/s41433-020-0830-3

Wong, E. W. N., Lai, A. C.-h., Lam, R. F., & Lai, F. H. P. (2020). Laser-induced ocular injury: a narrative review. Hong Kong Journal of Ophthalmology, 24(2).