Why can i see better some days than others ? some days vision shows good detail and then its cloudy things look like i used a smoothed out effect

Fluctuating vision: A number of things can make vision fluctuate. Allergy can cause a thin film of mucus that blurs vision as you describe. Dry eye can do the same. Thick meibomian oil in rosacea or blepharitis can also temporarily cloud vision. Beyond that, large changes in blood sugar can cause changes in vision requiring glasses. Eye strain can occur from long periods of cell phone or computer use.