When Gandhari married Dhritarashtra, she took an extremely severe oath of remaining blind-folded all her life.Was Gandhari in any way inspired by the example of Bhishma, who was in fact the great Kshatriya who came to her father, asking for her hand in marriage to prince Dhritarashtra?
Gandhari has blindfolded her eyes because of love and respect towards her husband Dhritarashtra. I don't think there is a role or impact of Bhishma on this incident.
It is mentioned in Sambhava Parva of Adi Parva, Mahabharata.
Soon after Bhishma heard from the Brahmanas that Gandhari, the amiable daughter of Suvala, having worshipped Hara (Siva) had obtained from the deity the boon that she should have a century of sons. Bhishma, the grandfather of the Kurus, having heard this, sent messengers unto the king of Gandhara. King Suvala at first hesitated on account of the blindness of the bridegroom, but taking into consideration the blood of the Kurus, their fame and behaviour, he gave his virtuous daughter unto Dhritarashtra and the chaste Gandhari hearing that Dhritarashtra was blind and that her parents had consented to marry her to him, from love and respect for her future husband, blindfolded her own eyes. Sakuni, the son of Suvala, bringing unto the Kurus his sister endued with youth and beauty, formally gave her away unto Dhritarashtra.
There was one exception of Gandhari opening her eyes.
Conversant with the rules of righteousness, the Kuru queen, possessed of great foresight, directed her eyes, from within the folds of the cloth that covered them, to the tip of Yudhishthira’s toe, as the prince, with body bent forwards, was about to fall down at her feet. At this, the king, whose nails had before this been all very beautiful, came to have a sore nail on his toe.
According to 1998 Mahabharat series, Gandhari felt it an honor to marry Dhritarashtra. Even if she were to lose her beauty, it wouldn't matter because Dhritarashtra couldn't see anyway.
Later in the series (I think during Mahabharat war, or before it), Gandhari says she didn't want to refuse anything to someone as great as Bhishma.
As for the actual blindfolding, she says it's wife's duty to share husband's world. In this case, a world of blindless.