The Prophet (sallallahu alaihi wa sallam) was well aware of the incredible benefits of Kohl Ithmid and this is why he himself applied it regularly to his eyes and ordered his Companions to do so. This sunnah is a must for Muslims to practice. It cleanses the eyes, beautifies them and promotes eye health and eyelash growth. It also repels flies due to its aseptic properties.
Kohl is a natural mineral stone. It consists of lead and antimony. When it is ground to a fine powder it is called Ithmid. This is a very pure form of kohl and is considered superior to other types as it has very few sparks when rubbed against the skin and does not scratch up the eye. This type of kohl is usually grey in colour, but some are black as well. The quality of ithmid can be assessed by looking at how shiny the particles are. If the ithmid is very sparkly, this means that the particle size is too large and can scratch up the eye.
Ithmid is also thought to protect the eyes from harsh sunlight by absorbing UV rays which are harmful to the eye sight. Some research indicates that it contains lead ions that stimulate the production of nitric oxide which lowers intraocular pressure and acts as a vasodilator, thereby reducing the risk of eye diseases. Kohl Ithmid