The advice from doctors is usually to look away when having injections, but people having root canal treatment and other surgeries might want to look at the needle before it goes in to their body.
A new study by researchers at University College London and University of Milan-Bicocca has found that the brain is more able to tolerate pain when it can see the cause than when it cannot.
Scientists used heat probes on the hands of subjects and found that they were able to withstand higher temperatures when they could see their hand than they could when it was blocked by a screen.
Co-author Professor Patrick Haggard told BBC News: "We've shown there is an interesting interaction between the brain's visual networks and the brain's pain networks."
Back in November 2010, scientists at Kings College, Brunel University and the London South Bank University announced they had created a device that cancels out the noise of the dentist's drill while still allowing the patient to hear the dentist and other sounds.