Having blinds at home in Spain is completely normal, in fact, it is expected that houses have blinds. In contrast, in other countries they do not exist and only use curtains to block out the light.
Origin
Doing a Google search, we find that the term persiana comes from the Latin "persa,-ae", which means "originating from Persia". It seems that the blind, as such, first arrived in Europe in the 18th century, in Venice to be precise.
But actually the first to patent this system was the English physicist Edward Bevan in 1769. He invented a device made of movable wooden slats that could be operated by means of a cord and a pulley fitted into a frame. It is curious that it was an Englishman who invented the roller shutter when in the Nordic countries, the Netherlands, Belgium, Germany, etc. they are not used. There are two reasons for this. On the one hand, they tend to trap the little sun that reaches them when here we need to avoid it in order not to overheat the buildings. On the other hand, the Protestant currents that settled in those areas of Europe changed the concept of privacy and hiding behind a blind could give the impression that you were hiding something. Translated with www.DeepL.com/Translator (free version)
Blinds in Spain
Finally, shutters have become part of the building industry in Spain. So much so that we even have a diversity of blinds. Some are very charming, such as the esparto grass blinds that can be seen in many villages in Andalusia and Extremadura. There are also horizontal blinds, whose slats hang like curtains, Roman blinds, roller blinds or Japanese panels, which can be installed on large windows or sliding doors thanks to their rail system. Translated with www.DeepL.com/Translator (free version)
Roller blinds are the most widespread system in Spain and the truth is that they are an excellent light control system, they serve as solar protection and they can improve the protection of the home with certain self-locking security systems. But they also have several disadvantages, such as being a weak point in the thermal envelope, among other reasons why this system is not used in other countries. Translated with www.DeepL.com/Translator (free version)