How Do Glasses Correct Visual Problems?

Glasses are the most common tool people use to correct their vision.

Eyeglasses correct the vision of those with sight eye problems when worn, but glasses are not a permanent solution. They change the direction of light so it hits the eye in a way that sends clear pictures to the brain.

How You See

The retina is the part of the eye upon which images are focused and sent to the brain. When the eye is functioning properly, it bends the rays of light as they enter the eye so an image is focused sharply on the retina. Eyeglasses work by bending the light to ensure sharp focus of an image on the retina.

Nearsightedness and Farsightedness

Those who are nearsighted see near images clearly. The eyes in this case focus the image in the front of the retina instead of directly on it. Those who are farsighted see far away images clearly, and the eyes focus the image behind the retina.

Corrective Processes of Eyeglasses

Glasses are concave -- curving inward in a kind of hourglass shape -- to correct nearsightedness. This expands the light so that it focuses farther back in the eye, directly on the retina. Glasses are convex -- curving outward into a kind of oval shape -- to correct farsightedness. This narrows the light so that it focuses further inside of the eye, directly on the retina.

References

• Kids Health: Glasses and Contact Lenses
• University of Washington: Neuroscience for Kids--Glasses

Resources

• WebMD: Eye Care Center