Does blepharitis causes blurry vision?

Certainly can!: Typically blepharitis causes the eyes to have foreign body sensation, feel life there is sand or dirt in the eye, and there is a burning sensation. Sometimes also itchy. The tear film becomes unstable with fluctuating vision. In much more advanced cases there can be ulcerations of the cornea, loss of the limbal stem cells and loss of clarity of vision.

To a minor degree: Blepharitis is a dandruff like inflammation of the lids which can lead to the shedding of debris into the eye causing irritation and minor visual disturbance. It does no actual harm to the eye so the visual change is temporarly. Check with you ophthalmologist to treat your blepharitis.