Heat exposer to the iris?

If the eye is exposed to extremely hot heat can it effect the pigments in the iris causing the color in the iris to fade.

Heat exposer to the iris?
Inside every normal eye there is a lens which puts what we look at into clear focus. The picture of everything that we see must enter our eye through this lens on its way to the back of the eye. This situation is very similar to the working of a camera, where light must travel through the lens on its way to the film. As in a camera, the lens of the eye is normally crystal clear and is capable of producing sharp pictures. Under some circumstances, however, this lens becomes cloudy and light does not pass through it easily.


It is this clouding of the otherwise clear natural lens which is termed a cataract. A cataract is not a growth, a tumor, or a film. Nor is it on the outside of the eye, as some people believe. Rather, a cataract is a clouding, or haziness, of the lens inside the eye. If everyone lives long enough, everyone will get cataracts. The point in time when a cataract affects real world useful vision (not Snellen visual acuity) is variable from person to personAs the cataract advances, colors become washed out. All of these changes can occur before the snelling visual acuity test (wall chart letter test) is abnormal. In other words, your visual acuity can be a perfect 20/20 but your quality of vision is not good.


Your eyes are very susceptible to high-intensity short-wave infrared radiation. Long-term exposure to infrared radiation can permanently damage the eyes. Glass blowers and arc welders, for instance, who are exposed to large amounts of infrared irradiation over time, are susceptible to depigmentation of the iris and opacity of the aqueous humor, also known as "glass-blowers' cataract." Goggles with special infrared absorbing glass should be worn by people experiencing long-term exposure to infrared radiation.
Reply:The color of the iris depends on the amount and type of different pigments. Melanocytes produce dark pigments (melanin) which absorbs light. The entire back portion of the iris is almost black from this pigment. The front of the iris is an area of different pigments in different places that produce the color of the eye. In front of the iris is the aqueous in the anterior chamber. This fluid is made behind the iris in the ciliary body, moves forwards around the surface of the lens, out through the pupil into the anterior chamber. If one looks carefully at the aqueous one can see that the front part (behind the cornea) moves down, and the back part near the iris itself moves up, causing a sort of vertical circulation.





The amount of heat you are indicating would have to go through the cornea, which is fairly sensitive....and you'd close your eye before any significant 'heat' was absorbed because it would HURT.





Then the 'heat' energy would have to get through the aqueous which would cool it a bit more, ...then it would have to 'heat' the melanin or other pigment enough to cause it to become 'damaged'.


Now you have a damaged iris, and you can't go outside or in the light at all because it hurts too much to be in light, really hurts. People with Irita's (inflammation of the iris) have terrible photophobia.





Seems that it would take a lot of 'heat' to cause a significant change in iris pigments without causing other damage to other structures.





You were 'made' you. You are the 'only' you on the planet, and here for an instant. No one else like you.





NO ONE CARES about the color of someone Else's iris, someone Else's eye color. We 'like' that color on her, or him, yes it does look really nice...but if the person is a jerk, the eye color goes out the window in a flash.





Socrates was a short, heavy, bald man who everyone around, loved. It was what he said, how he thought, how he taught...that made people admire him, follow him, love him. I'm not sure what color his eyes were. You?