You Need Glasses
When your eyeball is shaped more like an egg than round, or your cornea or your lens isn't curved just so, light can't focus in the right spot. That can lead to seeing clearly only at certain distances (nearsighted and farsighted) and distorted vision (astigmatism). You can often correct these "refractive errors" with eyeglasses, contact lenses, or minor surgery.
Your Eyes May Be Tired or Dry
Have you been staring at a screen or page or focusing on a task for a long time? People tend to blink less often when they're concentrating like that. And each time you blink, you're spreading tears across the surface of your eye to keep it lubricated, clean, and refreshed. You may need to remind yourself to blink more often, take breaks, and look around to prevent vision fatigue. It can also be helpful to use artificial tears during the day to help keep your eyes lubricated.
You Have Diabetes
When your blood sugar isn't well-controlled, fluid may seep into the lens of your eye and make it swell. This can happen before you're diagnosed or if you're changing your treatment, like starting insulin. As your glucose level gets back to normal, the lens should, too. People with diabetes are more likely to get retinopathy, or bleeding in the back of your eye, and other eye problems, which your eye doctor will check for at your yearly exam.
Your Blood Pressure Is Low
Feeling weak and dizzy, too? Your blood pressure might be too low because you're dehydrated -- maybe from too much activity in the hot sun. Things like some medications, heart problems, poor nutrition, and hormone imbalances could also cause low blood pressure and related blurry vision.
