The Iris and The Pupil
 The iris is the colored portion of the eye. It is a membrane that is located between the cornea and the lens. Its round, central opening (the pupil) regulates the entrance of light into the eye by contracting and dilating. In fact, the iris is embedded with involuntary tiny muscles that dilate (widen) and constrict (narrow) the pupil size.  Round, around the edge of the pupil, lies what is called the sphincter muscle. When the light falling on the eye is bright, the sphincter contracts; and as the sphincter contracts, the pupil goes constricted. The compementary muscle to the sphincter is the dilator muscle that runs radially through the iris. When the light falling on the eye is dim, the dilator contracts; and as the dilator contracts, the pupil goes dilated. Thus the amount of light that goes inside the eye, is controlled through these two involuntary muscles. They react to emotions too! Something interesting constricts the iris that turns the eyes dilated in order to allow more light in and enable seeing the object of interest better.  In fact, it is a flat membrane that acts as a wall between the anterior chamber and the posterior chamber. It gets its color from microscopic pigment cells called melanin. It actually contains the melanin in it, that is a brown pigment. The more you have it, the darker you eyes appear. Blued-eyed people have melanin at the back of the iris, but hardly anywhere else. Brown-eyed people have plenty of melanin scattered around the iris. Pink-eyed people (albinos) lack almost all pigment in their bodies. In them the light reflects off the back of the eye, where the blood vessels are; and that is what makes their eyes appear reddish-pink. In fact, since the pupil is just a hole in the middle of the iris, it simply passes the light through; and the eye gets what is so fondly called its unique color! Every single person's iris with its unique color, its unique texture, and its unique patterns acts as the personal biological signature of the person concerned. A perfectly healthy human eye can see only one part of everything it looks at, the best; and all other parts relatively worse than that. Such an eye is said to have the most acute vision through central fixation. An eye with any kind of vision problems (which most people have - whether apparent or latent) - loses this central fixation and gets rather economically fixated. The only way out is to get that central fixation back (possible!) through vision therapy. I invite you to subscribe to my weekly E-zine titled Third Eye-zine. This weekly E-zine publishes rare, revolutionary articles which are of real use in the day-to-day life of a common man, covering topics concerning the effect of third eye opening on health, diseases, personality, performance, efficiency, relationship, sex, mind, creativity, passion, business, management, and energy level of a person; apart from its effect on vision correction. A not-to-be-missed opportunity! Subscribe to it here: I also invite you to subscribe to my Third Eye Blog - no need to provide your e-mail address here. This RSS feed keeps you informed about new developments taking place on this site. It also harbors my weekly Third Eye Bloglet narrating My Story : My Date with My Body - a bloglet about vision, mind, sex, science, and society. A real interesting reading! In order to subscribe to the blog, right-click on the orange RSS button (see buttons up to the left) and then paste the URL into your RSS reader. Or click on add to My Yahoo! button or My MSN or Add To Google button if you keep a personalized home page there. If you are not sure what RSS or blogging is all about, click on What's an RSS Feed? here:
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