The glitch

The glitch is a series of malfunctions experienced by Adam Jensen and other mechanically augmented people in the game Deus Ex: Human Revolution. It appears to cause pain, disorientation and loss of control of augmented limbs. For those with mechanically augmented eyes it seems to cause interference to vision and the heads up display.

Examples of the glitch
Adam Jensen experiences several glitches, one of which prevents him properly interrogating Isaias Sandoval if he does not attempt suicide and instead chooses to fight. On two occasions the glitch can be seen afflicting several people besides Jensen, causing them to stumble and fall over. Two Harvesters can be overheard talking about the problem they experienced while trying to steal someone's limb.

Origin of the glitch
The glitch is caused by the Illuminati, possibly through Tai Yong Medical and using the research of Megan Reed's team as a way to persuade augmented people to replace their biochip with a version that would allow them to shut down augmentations at will.

Several e-mails can be found regarding the glitch. A comment at the start of the game refers to the glitch. "I have spoken with Montreal. The broadcast satellites are ours when we need them. A few weeks of discomfort, and the public will be primed for our recall."

There are other things that will impair the function of augmentation other than the glitch. EMP grenades will force the HUD to reboot and dying will scramble the HUD. Having the new biochip installed allows mechanical augmentations, including the HUD, to be shut off with a specific signal.