The phrase "are often perceived by" is correct and usable in written English.
It can be used when discussing how certain ideas, actions, or phenomena are viewed or understood by people or groups.
Example: "Cultural practices are often perceived by outsiders as strange or unusual."
Alternatives: "are frequently viewed by" or "are commonly seen by".
They are often perceived by farmers as having negative impacts on agricultural production.
These areas are often perceived by farmers as potential breeding habitats of animals and plants that are harmful to crops.
Seasonally used pastoralist lands are often perceived by outsiders as 'unused' and therefore may be subject to attempts by government authorities to allocate them in this way (Mattee and Shem 2006).
Among the barriers to learning science are the persistent emphasis on factual memorization, rigidity of the curriculum, and a lack of real world applications, problems which are often perceived by students in a 'traditional' science class (Tobias 1990).
Topics that involve math are often perceived by students as being less accessible (Betz 1978; Metz 2008), and mathematical anxiety can thwart motivation to achieve and critical thinking applications, like adapting to novel uses (Cates and Rhymer 2003; Zakaria and Nordin 2008).
Despite this they are often perceived by parents as problematic consultations [ 3, 4].
She hid her body beneath baggy clothes, identified as a lesbian and was often perceived by strangers to be an adolescent boy.
It also suggests that nowadays satire is often perceived by its target as a badge of honor, or, at worst, as simply another media mention or product placement.
For Brazil, the three are forests, sex and football.That the world's fifth-largest country (by population) and eighth-largest economy (in real terms) is often perceived by foreigners as a giant Club Med resort is partly thanks to foreign correspondents reporting on Brazil, who often feel they have to start with what readers back home know about the place and go from there.
Overcrowding in the emergency department is a problem that is often perceived by the staff but hard to determine quantitatively.
Brake squeal is a source of significant warranty-related claims for automotive manufacturers because it is annoying and is often perceived by customers as a safety concern.
