Why do I have a haze appearance on my windows?

Haze can occur on most coated glass. However, the effect will be more noticeable on some types of coated glass than on others. Haze gives the appearance of a fine, uniform, layer of dust deposited on the surface of the glass. The effect is more noticeable when the glass is viewed at an angle or under strong light. In situations where the glass is in partial shadow, the shaded area will be free of the effect, giving a clean appearance in the shadow and a dusty appearance in the lit area. This contrast can be very noticeable. Hard coated low-E glass can manifest this effect. The reason for this is that coating is not as smooth as the glass surface. This 'roughness' of the coating is not apparent to the human eye. This 'roughness' scatters a small proportion of the light striking the surf