Ithmid kohl (a.k.a. kajal or surma) have been used for thousands of years as eyeliner for the eye. But it isn’t only for aesthetics. Ithmid kohl has been used in the past medicinally to treat eye related ailments, and the benefits are even shown in some scientific studies. Note that Ithmid kohl refers to the pure powdered mineral of Galena, which is essentially lead sulfide.

UV Blocker

So what are the benefits of Ithmid kohl? Well firstly, it provides protection against ultraviolet (UV) radiation from the sun. The Galena that the kohl is made out of has UV absorptive properties, so when the user applies the powderized galena kohl to the eyes the microscopic particles of galena form a thin film over the eye and absorbs the incoming UV rays from the sun. And given that galena is dark grey & shiny, it also helps reflect off the bright glare from the sun. Consider that black or dark colored objects have nearly all the light touching it absorbed by its surface, so that nearly none is reflected back to your eye. That’s why it looks opaque to you.

The reason why its important that ithmid kohl absorbs the UV rays is because excessive exposure of sunlight to the eyes is a risk factor for macular degeneration. Macular degeneration refers to the back of the eye deteriorating, which is where the retina is connected to the eye. This causes the center of one’s vision to blur or be totally lost.

Nitric Oxide Booster

The secondary main benefit of Ithmid kohl is that it promotes the production of Nitric Oxide in the eye. Raising the level of Nitric Oxide (NO) has a wide range of benefits, one of which is improving the immune system’s ability to fight infections. The process by which NO levels are raised starts with the lead sulfide’s Pb2 + ions stimulating keratinocytes (cells that make up the outermost layer of the eye, like the cornea) to undergo an oxidative stress response, which includes the overproduction of nitric oxide.

Nitric Oxide (NO) itself cannot be used as a drug, because it quickly breaks down in a few seconds. So finds ways to stimulate the body’s own production of NO is better.

Coming back to the benefits of Nitric Oxide, they include antimicrobial, anti-tumor, vasodilating, anti-inflammatory, and intraocular pressure lowering properties.

Antimicrobial

Nitric oxide is effective against gram-negative, gram-positive, and even antibiotic resistant bacteria such as MRSA (methicillin-resistant staphylococcus aureus). The broad-range antibacterial property of nitric oxide comes from its reactive by-products, peoxynitrite & dinitrogen trioxide.

So stimulating the body’s own natural production of Nitric Oxide may be a better alternative than to antibiotics that microbes eventually become resistant to. Antibiotics kill off both good & bad bacteria living in your digestive system, which is a problem because it gives bad microbes like clostridium difficile a chance to take over your GI tracts. That’s why people who overtake too many antibiotics usually have autoimmune diseases, allergies, and IBS- they end up negatively changing their microbiome with excess antibiotic use.

As a side note, some studies looked at whether lead sulfide has antimicrobial properties. According to those studies, lead sulfide itself has low antimicrobial properties. However, they fail to realize that lead sulfide elicits an very strong antimicrobial effect by raising the level of Nitric Oxide in the eye. That’s how it works. So be careful and don’t take every study or other piece of information at face-value.

Vasodilation

Nitric oxide is a vasodilator for blood vessels, which means it widens the blood vessels and allows for more blood to circulate. Nitric Oxide controls basal blood flow in the optic nerve, choroid, and retina. And certain ocular diseases are caused by a lack of proper blood flow to the eye. For example, a lack of blood flow to the eye can cause macular degeneration.

Specifically, there is not enough blood flow to the macula of the eye in macular degeneration. The macula is the back part of the eye where the retina connects to.

Also consider that smoking is a strong risk factor for macular degeneration, not only because smoking exposes toxic compounds to the body, but also because the nicotine in tobacco is a vasoconstrictor, meaning that it reduces the width of blood vessels to let less blood through.

So if less blood flow is a risk factor for muscular degeneration, then surely increasing blood flow to the eye is a prophylactic (preventative) measure against ocular diseases. That’s truly the case, given that exercise is a prophylactic against macular degeneration due to improving the vascular function of the eye (and the rest of the body). And nitric oxides has a similar function in dilating the blood vessels. So that’s another way ithmid kohl can benefit the eye by improving ocular blood circulation.

Intraocular Pressure

Nitric Oxide also lowers intraocular pressure (IOP), or the pressure inside of the eye. When the pressure inside of the eye is too high, it leads to ocular pathologies like glacoma.

Glaucoma is the leading cause of permanent blindness on earth, and is characterized with first peripheral vision loss followed by central vision loss. Glacoma is the name for various disease conditions of the eye that damages the optic nerve damage to cause vision loss. The primary one is high intraocular pressure. Other lesser risk factors for glacoma include ischemia (reduced blood flow), inflammation, hypertension, myopia, race and age. Notice that smoking qualifies for many of these risk factors. Anyways, if you are able to reduce IOP, it controls and prevents the progressions of glacoma.

Nitric oxide is able to lower IOP and improve the optic nerve head perfusion of the eye. So ithmid kohl, which is able to raise ocular NO levels, can help treat glacoma in this respect.

Sources

History of Toxicology and Environmental Health : Chapter 7 :: Kohl Use in Antiquity: Effects on the Eye [ResearchGate] A Review of Nitric Oxide for the Treatment of Glaucomatous Disease [Ophthalmol Ther.]