Completely obvious at a glance; plainly evident.
グラフを見ると売上の増加は一目瞭然だ。
Looking at the graph, the increase in sales is obvious at a glance.
書類の間違いは一目瞭然で、すぐに訂正が必要だった。
The mistake in the document was obvious at a glance and needed immediate correction.
新しいデザインは前のものより分かりやすくて、違いは一目瞭然だ。
The new design is clearer than the previous one; the difference is plain to see.