Different wavelengths of light penetrate to different depths below the skin surface and are absorbed by different skin or tissue components. For example CO2 and Erbium laser light is absorbed by the water in cells exposed to it. Flahslamp laser light is absorbed by red blood cells. Nd:Yag laser light is absorbed by skin pigment cell melanin and tattoo pigment. Since the eyes contain water, pigment cells, red blood cells etc they can be damaged if exposed to most laser lights either directly or indirectly (from reflected laser light). Even the laser pointers used by lecturers can damage the eye if pointed directly into the eye. Some lasers such as the CO2 have a beam whose wavelength is not visible by the human eye but they can still cause damage to the eye. The CO2 and Erbium will damage the cornea and surface of the eyeball first. Flashlamp and vascular lasers are absorbed by red blood cells and are the most damaging to the eye as they are absorbed by and damage the retina.
For safe laser use one should never look directly into the laser light source or scattered laser light from reflected surfaces. All laser treatments should be performed in treatment rooms or operating rooms that are not open to the public. All persons in the treatment area must wear protective goggles or glasses with side shields. A laser safety sign should be placed outside the door of these treatment rooms so that nobody inadvertently opens the door and gets eye exposure to the lasers being used. Because of the wide variety of wavelengths used in laser treatments today the goggles have to block the specific wavelengths employed. Goggles that block 1064nm wavelength light used to remove black tatoos will usually not block out 532nm wavelength light used to remove red tattoos. All laser safety goggles have the wavelengths they block written on the edge of the lenses. Whenever I use a laser facility for the first time I check the numbers on the goggles before I give them to the patient or put them on myself. If the laser treatment is applied directly to the eyelids metallic dulled eye shields that look like large contact lenses should be placed directly on the eyeball surface.
Intense Pulsed Light or IPL is basically a strobe light of multiple wavelengths used to treat freckles or uneven skin coloration. Technically it is not a laser but it can still damage the eyes even if the eyelids are closed and the IPL treatment is directed at a freckle on the eyelid skin. There are reports of photophobia, iris defects and inflammatory reaction in the anterior chamber of the eye after such treatments. Irreparable damage of the iris (colored ring around the pupil) is the cause of most these problem.
If you suspect that your eyes have been damaged by a laser or IPL treatment you need to be examined by an Ophthalmologist as soon as possible.