Do you live in a hard-water area? Hard water has a high mineral count, and the calcium deposits often leave marks or calcium build-up wherever water is used. In particular, frequent dishwashing using hard water could cause glassware and plasticware, such as drinking glasses and your baby's feeding bottles, to be blurry.
Here's how you can prevent this: Wet a dish rag with a few tablespoons of white vinegar -- just enough to make it damp -- and use it to wipe your clean glasses and bottles. Alternately, you could also add 2 cups of vinegar to a pan of hot water and give your wares a quick soak. Let dry. Don't worry, there won't be any traces of vinegar smell or taste.