How can contrast sensitivity affect night driving?

?: Need more info. Contrast to what? Considering you had glaucoma only your ophthalmologist can give you a correct answer.

Difficulty seeing: Low contrast sensitivity means that if it is difficult to see an object when its color is close to the surrounding environment. Contrast is reduced when light is reduced; so low light situations such at night and in the rain make objects harder to see. This can become dangerous. Cataracts are the most common cause of reduced contrast sensitivity in older adults.