Well too you can visit the dark side and use a 140dB ultrasonic speaker(s)....a dog whistle....this will not so much be heard but will cause nausea and vomiting and pain first then over time it will permanently physiologically damage the hearing apparatus and then scatter some retinal (just the top layer) burning laser light via a disco ball and you will be all set. The ultrasonic sound typically has an omni directional sense to it because you feel it more than hear it.
Ultrasonic Sound...
It depends on their intensity or amplitude and tieme of exposure. There is a device of frequency around 20 kHz that were used in public squares in France some years ago to keep younger people out of the square at night, the principle of this device is that only younger people could hear that frequency so in emitting a “semi”-high ultrasonic wave (that propagate in air) the younger people couldn’t stay near the source of the sound causing dissing and headcheese, this work in the same way to keep away mice and mosquitoes.
However if you use high intensity ultrasound you could have acoustic cavitation, and that could cause damage (i.e, acoustic cavitation bubbles can destroy objects near them) and the HIFU ultrasound also can make damage to the tissues
Laser light ...
If you were exposed in the eye to a direct laser beam, do not unduly worry. A beam in the eye may cause temporary flashblindness and afterimages. This is not an injury. Instead, this is the eye’s normal response to overly bright light. It is similar to what happens after looking directly into a camera flash. The afterimage area looks like a blob if you looked directly at the light, or can look like separate spots or a line if the eye was moving during the exposure.
Afterimages take about 5 or 10 minutes to fade. If after this time the spots are still visible, you may have retinal damage. Fortunately, this often heals within a few days or weeks. This is similar to how your skin heals after getting a small cut or a bruise. Vision may return completely to normal, or you may have faint spots noticeable only under special conditions such as looking at a uniform white wall or blue sky. An Amsler Grid test can help in finding small lesions within 8-10 degrees of the fovea.
