Does commitment to ideology make us blind to objective understanding?

From: Keshav
Is the Marxist view that , ” Idealogy leads to blindness after a distance ” true ?
Any person in real life follows a idealogy and also the truth is relative for everyone ,so how can one be sure of his path ?
When a person follows a idealogy ,his thoughts , his intellect works according to  his idealogy ,but his idealogy can not answer every question . Does owing to a idealogy closes doors for open thinking and knowledge of the absolute truth ?