"A type of laser medium that produces a visible blue-green wavelength beam that is absorbed by red-brown pigmented tissue, such as the red hemoglobin in blood, and by the cells that lie under the retina, is a(n)"

ARGON LASER

Explanation: An Argon laser is a type of unique laser system that was invented in 1964,it is unique because it uses a noble gas (ARGON) as it's active medium. Argon laser functions by emitting a colored light of blue/green,this light is being absorbed by haemoglobin present in blood cells,the heat produced gives room/allows the laser to close up cells of blood that are ruptured.

hypoxemia refers to a below usual concentration of oxygen in the blood, mainly in the arteries. hypoxemia is an indication of an issue associated with circulation or breathing and may lead to various symptoms like shortness of breath.  

the condition is identified by determining the level of oxygen in the blood sample obtained from an artery. it can also be predicted by determining the oxygen saturation of the blood with the application of a pulse oximeter.  

the normal arterial oxygen is about 75 to 100 mm hg. the values underneath 60 mm hg is generally considered with the requirement for supplemental oxygen. the normal pulse oximeter readings generally range between 95 to 100 percent. the values under 90 percent are regarded as low.  

in the given case, the oxygen saturation is measured at 93 percent, hence, there is no need to administer oxygen, that is, one should withhold oxygen.