Disclaimer- anything said here by myself is not intended to be taken as medical advice and/or treatment and does not constitute a traditional doctor/patient relationship. It is for educational and entertainment purposes only. You should always seek the attention of your own personal physician for medical services.



Hate that I have to do that.....



I should also state that I am not an ophthalmologist but I do have specific knowledge of this area and have access to the latest publications.



There is a few decent publicly available articles available on the web regarding retinal and general laser eye injuries, you can search for "accidental retina laser injury" or similar and come up with quite a few good reads.



In general, most serious laser injuries do not respond very favorably to any specific treatments. That means "wear your eye protection!" Because not only is prevention the best treatment, it is really the only treatment. There are different grading scales of injury that range from essentially a "stunned" retina all the way to full out necrosis and coagulation of the back of the eyeball. What makes eyes and lasers like matches and gasoline is the retina is a very sensitive and fragile organ that exposes itself to the outside world through a magnifying lens. Everything you are looking at right now, your entire visual field, is focused on an area in the order of a few millimeters. The most sensitive and densely packed area that gives you your precision of acuity is only a small fraction of this area near the middle of the focused light coming onto the retina. So, most of what allows you to see precisely and do things like read and recognize images is all in the area of a few square millimeters. Next, it has this big thing in front of it called a lens, a big magnifying lens. Add this with collimated light between 400 and 1400nm with measurable power and you have the perfect makings for a disastrous outcome. The laser, already highly concentrated, is focused even more onto a very small and important area that lacks the ability to regenerate itself like some other tissues and organs do.



Early studies of laser injury to the retina proved it only took about 7 to 10 mW to cause measurable damage to the Rhesus monkey's retina. Although there is some dependence on wavelength, in general it doesn't take but three to four times this to cause irreparable injury in some. There are many factors that play into how much power causes how much damage to a certain individual including lens age and clarity, astigmatism, myopia, and length of exposure. It is pretty intuitive that the lower the power the more time of exposure is required to cause retinal injury. Put all this aside and just realize it doesn't take much, especially with the power most of us tend to play with around here. When you're talking about watts your blink protective response is useless to prevent damage. You can't blink fast enough at this level of power, all the damage is done before the first neuron in the reflex pathway releases it's neurotransmitters into the next synapse. Forget the next few milliseconds it requires to activate the muscle and close the lid, the retina is already fried.



Painful? Sorry Charlie. Rarely are laser injuries gauged by perceived pain, they are generally painless with a few exceptions. Your now just blind in your visual field where that part of the retina is now a necrotic and coagulated area of soon to be irreversible scar tissue without function.



At this point a few treatments have been attempted like high dose steroids and non-steroidal anti-inflamitoies. None of these have been proven effective at doing much. The thought being that the resulting area of inflammation around the laser burn may continue to be damaged and the visual loss may even increase with time, these drugs may be of benefit but none have been proven so. Interestingly, sometimes laser surgery can be used to try to remove some of the scar tissue affecting the surrounding retina but this has limited benefit too. There are lesser degrees of damage that can occur and cause irreparable injury over a longer time than a flash burn takes. Here again, while this has been identified as a process of damage, not much seems to be helpful. Steroids are a often tried but some now think this may be counterproductive. There are other mechanisms of damage that occur as a late phenomenon that are too technical to describe here, but the point of bringing this up is that it may be useful to see an eye doctor to try to identify these processes and minimize their impact.



So far I have only described retinal injury. There are other parts of the eye that can be damaged as well. Although not as dramatic initially, they can also prove to be debilitating and even disfiguring. Scleral burns, cataracts, and even possibly glaucoma may result.



So, if you think you've fried your retina, be sure to make the trip to the doctor useful by stopping along the way to pick up some eye safety wear. That will likely be the best outcome from a trip to the ophthalmologist, preventing your next injury. Other than staging your injury, not much else is likely to be of much benefit from him or her.



Here is a little suggestion for the newbie thinking of building or buying one of these fabulous lasers we enjoy around here. If what I've just said above is the first time you've heard about these injuries then you are probably not ready to own one. You probably haven't read the stickies in the areas about safety and eye protection. This is a must before attempting to build or buy one of these cool 445nm 2w handhelds, or any other laser over a few watts you couldn't easily buy at the local corner store.



I think it's worth repeating, prevention is the best medicine because in the end, it's really the only good medicine when it comes to laser injuries. God only gave you about 4 to 5 square millimeters of retina to last a lifetime. Don't show Him and all of us here how foolish and ungrateful you are by wasting them over a few seconds of excitement without taking the time to learn how to protect them first.