They are not just useless, but can kill you or make you blind.
When my wife’s grandmother was giving up her apartment, she asked if I wanted a few ties she had in a suitcase. In fact, there were hundreds; her husband went to the racetrack every week after buying a new tie for good luck, and if he lost he never wore it again; I still wear them. Back then, everybody wore ties, all the time -- even, as John Kennedy did, to the ball game.
But it turns out that Grandpa Hugh might have had better luck and picked better horses if he had left the tie at home; a new study has concluded that neckties cut blood circulation to the brain.
The abstract of the paywalled study, Should you stop wearing neckties?— wearing a tight necktie reduces cerebral blood flow, describes how the researchers examined thirty volunteers.
Thirty volunteers were divided in two groups. One underwent MRI with necktie, the other without. The examination resulted in a statistically significant [7.5 percent!] decrease of CBF [cerebral blood flow] after tightening the necktie, while the venous flow did not show any significant changes.
Ned Dymoke of the Big Think suggests that's “enough to make a potentially fatal difference if you already have high blood pressure.” He also points to an older study that found that Tight ties may be bad for eyes.
According to Robert Ritch, the eye specialist at the New York Eye and Ear Infirmary who led the work, a tight tie compresses the jugular vein, causing a backup of blood along the system to the eye, thus raising the pressure. “This external cause of raised intraocular pressure could possibly contribute to further damage from glaucoma,” he says.
From a design point of view, I have never understood the point of ties; they serve no useful function now that collars have buttons. And now the world has changed from where people dressed up for airplanes, horseraces and theaters. Google, Apple and Amazon have actually banned them; so have British hospitals, which consider them an infection risk.
I would only wear them when going to banks and funerals; but now that I know that they can kill you or make you blind, I may never wear one again.