As a little kid I once asked my father "how does the eye work". He brought me a picture in an encyclopedia showing a disection of an eye ball with all the parts being given their medical, technical names. But my thirst of knowledge was great so my father told me about Newton and light rays, the lenses and how they focus the image on the retina's surface.
My thirst was not yet quenched, but my father didn't know what else to say, and I grew unpatient. Later in life I learned that the image projecten on the retina is then turned into electric impulses that go to the brain, are converted into a state of your psyche and perceived as an image coming from your senses.
For me it's a bit miraculous and divine how it happens. Back to your question: I don't really think that there is an answer to it, because even if you take a single letter on your screen, all the voltage shifts that happen inside of the machine are very complex, multiple hardware elements take part in it, there is the graphics processor and the screen, the different memory parts and the operating system that manages everything. In such a complicated structure it is very hard to say what actually happens that you can see a group of pixels on your screen that represents a letter "A". And even if you take a very simple microcontroller and a simple display there is quite a lot of operations going on inside, the data being stored, pushed through the arithmetic and logic unit, through the registers and so on. So there is no simple answer as the letter "a" is not a simple high voltage state in one single transistor, and even if you look at a really single byte or an electric impulse it probably does nothing at all.
My thirst was not yet quenched, but my father didn't know what else to say, and I grew unpatient. Later in life I learned that the image projecten on the retina is then turned into electric impulses that go to the brain, are converted into a state of your psyche and perceived as an image coming from your senses.
For me it's a bit miraculous and divine how it happens. Back to your question: I don't really think that there is an answer to it, because even if you take a single letter on your screen, all the voltage shifts that happen inside of the machine are very complex, multiple hardware elements take part in it, there is the graphics processor and the screen, the different memory parts and the operating system that manages everything. In such a complicated structure it is very hard to say what actually happens that you can see a group of pixels on your screen that represents a letter "A". And even if you take a very simple microcontroller and a simple display there is quite a lot of operations going on inside, the data being stored, pushed through the arithmetic and logic unit, through the registers and so on. So there is no simple answer as the letter "a" is not a simple high voltage state in one single transistor, and even if you look at a really single byte or an electric impulse it probably does nothing at all.