The phrase "astounding effect" is correct and usable in written English.
It can be used to describe a remarkable or surprising impact that something has on a person or situation.
Example: "The magician's final trick had an astounding effect on the audience, leaving them in awe."
Alternatives: "stunning impact" or "remarkable influence."
This had an astounding effect, with an average 70% increase in visitor numbers: the V&A rose by 111% in the first year.
This survey of nine centuries of Russian art ranges from 13th-century religious icons to a smattering of 21st-century works, achieving its astounding effect without resorting to a single egg, or anything else, by Fabergé.
The bespectacled experimental duo of J Willgoose, Esq and Wrigglesworth have been turning heads with The War Room EP, a five-song concept piece wherein, having persuaded the BFI to grant them access to wartime propaganda films, they blend the voices of the past and the music of the present to astounding effect.
The laser-assisted surgery had an astounding effect on pain among our patients.
College Bound has an astounding effect on students and mentors alike.
Although the eruption was a century ago, one of its more visually astounding effects remains.
Taran Adarsh of Bollywood Hungama rated it 4 out of 5, calling it a "crowd-pleasing and hugely mass appealing tale of android revolution with a thrilling plot, rich and imaginative screenplay, super action, astounding effects and most importantly, Rajinikanth, who is the soul of the film.
Equities take less time to reach rock bottom but lose more than half of their value by the time they get there.The most astounding result, said Mr Rogoff, is the effect on public finances.
Oh and this is important bring a blanket, because, spoiler alert, there's this really astounding special effect that involves frostbite.
I've witnessed an astounding ripple effect of change; from my vantage point, nothing will ever be the same.
An astounding result given the times.
