Refractive errors are a type of vision problem that makes it hard to see clearly. They happen when the shape of your eye keeps light from focusing correctly on your retina (a light-sensitive layer of tissue in the back of your eye).

Refractive errors are the most common type of vision problem. More than 150 million Americans have a refractive error — but many don’t know that they could be seeing better. That’s why eye exams are so important.

If you have a refractive error, your eye doctor can prescribe eyeglasses or contact lenses to help you see clearly.

There are 4 common types of refractive errors:

• Nearsightedness (myopia) makes far-away objects look blurry
• Farsightedness (hyperopia) makes nearby objects look blurry
• Astigmatism can make far-away and nearby objects look blurry or distorted
• Presbyopia makes it hard for middle-aged and older adults to see things up close

The most common symptom is blurry vision. Other symptoms include:

• Double vision
• Hazy vision
• Seeing a glare or halo around bright lights
• Squinting
• Headaches
• Eye strain (when your eyes feel tired or sore)
• Trouble focusing when reading or looking at a computer