That's because research has shown that the harder your brain works, the more your pupils dilate.
However, when interpreting this indicator, you must also take in to consideration the illumination of the room, as in darker surroundings our pupils will naturally dilate to let in more light.
These avenanthramides have been linked lowering blood pressure levels by increasing the production of nitric oxide that helps dilate blood vessels, improving blood flow.
These avenanthramides have been linked lowering blood pressure levels by increasing the production of nitric oxide that helps dilate blood vessels, improving blood flow.
The study's lead researcher Dr Ajith Karunarathne, an assistant professor in the UT department of chemistry and biochemistry says we shouldn't be checking phones and tablets in the dark, because this can dilate the pupils making them more vulnerable to damage.
The team from the University of Toledo in Ohio says it is urging the public to not use phones in the dark because this can dilate pupils and lead to even more harmful blue light entering our eyes.
The team from the University of Toledo in Ohio says it is urging the public to not use phones in the dark because this can dilate pupils and lead to even more harmful blue light entering our eyes.
Music can cause the pupils to dilate and increase blood pressure, inducing a "state of arousal".
Nitric oxide molecules dilate blood vessels and help regulate blood pressure, along with a host of other benefits.
A nip or two actually causes your blood vessels to dilate, moving warm blood closer to the surface of your skin, making you feel warmer temporarily.
Tea has complex compounds called polyphenols which are believed to help the arteries to relax or dilate, thus enabling a smoother flow of blood.
