The eye is one of the integral components present in the human body. It is one of the sensory organs required for humans to perceive the environment (not the only one). The eye consists of the iris, pupil, lens, sclera, choroid, retina, and many other structures. Out of these structures, it is known that the iris contains information about the entire body. We can come to know about the abnormality in part of the body just by looking into the iris. Sounds fascinating, right! This blog is about the top 5 interesting facts related to the iris.


1. Controlling the process of vision

For those who don’t know what an iris is, it is nothing but a thin structure present in the eye that is responsible for controlling the size of the pupil, ultimately, aiding in the control of light sent to the retina. The light that falls onto the lens, gets focussed and directed to the retina where the rod and cone cells act as photoreceptors and convert them to electrical signals that get processed by the brain.

Hence by this process, we are able to visualize and perceive objects around us. In this process, the iris plays an important role in controlling the light to the retina. In the case of strong/bright light, the iris makes the pupil contract, hence protecting the retina from damage.

2. Eye color

Another important aspect of the iris is its color, The color of the eyeball is determined by the color of the iris. This color is based on genetics and the concentration of melanin. More melanin means brown color and less melanin means blue color. The following are the different types of iris colors recorded in the human population:-

  • Amber
  • Brown
  • Grey
  • Blue
  • Green
  • Red

One interesting disorder related to the iris is heterochromia in which one eye has a color and another eye has a different color. This is due to the variation in the concentration of melanin in those eyes. The reason is mostly due to genetic mutation. However, this disorder is rare in nature.

heterochromia- a rare genetic disorder causing different eye colors

3. Potent biometric

One characteristic feature of the iris is that it remains stable and unchanged for a very long time. Hence this can be used as a potent biometric along with a thumbprint. Iris scan is considered the new age biometric and many bigshots use iris scanning as security in advanced bank systems. Even in the movie Vikram, the iris scan of the Agent was used to unlock a secret chamber.

Iris scanning – a potent biometric

4. Iris clock

The condition of the entire body is reflected in the iris. This used to be a theory in the 18th century and based on which, the iridology chart was developed. The iris is assumed to be a clock and the chart is plotted. Based on the different times, the organs have been added to the map. For example, the pancreas is present in the region of 7:15 to 7:45, the lung is present from 2:10 to 2:15, and so on. Any abnormal black spots formed on those regions indicate that the particular organ in that region is abnormal.

For example, it is observed in a majority of diabetic population, that a black crypt is formed in the region corresponding to that of the pancreas. Hence using this ideology, we can early diagnose certain medical conditions/disorders pertaining to the organs in the human body.

Courtesy- Hussein, Sherif E., Osama A. Hassan, and Malcolm H. Granat. “Assessment of the potential iridology for diagnosing kidney disease using wavelet analysis and neural networks.” Biomedical Signal Processing and Control 8.6 (2013): 534-541.

5. Potent pre-diagnostic tool

Iridology is the medical imaging technique that is used to obtain a clear image of the iris. This can be taken under suitable lighting conditions. The major advantage of this method is that it doesn’t require any special conditions or equipment and is simple. On the other hand, one major problem associated with this method is that the light appears as a white spot on the iris due to reflection. However, this method is a good alternative for expensive medical imaging and is an excellent method for the early diagnosis of many disorders. Several research works have been done regarding the early diagnosis of diabetes mellitus in patients through iris images. Indeed this sounds fascinating!!

Iriscope- the imaging equipment used to obtain the image of the iris

Using iridology, they obtain the image of the iris. And then, they superimpose the resultant image over the transparent iridology chart to find which organ is abnormal. Nowadays, automated diagnosis is done using machine learning and artificial intelligence.

The iris is indeed an important structure of the eye, significantly contributing to vision, and is a potent diagnostic tool in the field of medical imaging. The iris is indeed an example of the greatness of the human body.


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