We often take it for granted when we put on a pair of glasses or pop in contact lenses, but there is a rich perceptive of science that allows us to correct our vision with these tools. Eyewear Candy Optical RX would like to share the fascinating world of optics and the science behind how glasses and contact lenses work to help us see the world more clearly.
How Does the Eye Work?
To better understand how prescription glasses or contacts work, it helps to know a little bit about the basic mechanics of the eye. Think of the eye as a camera. Light enters through the cornea and lens, both of which help focus the light onto the retina located at the back of the eye. The retina then transforms this light into electrical signals that travel to the brain through the optic nerve, giving us our vision. When the eye’s shape, lens, or both don’t focus light correctly, it results in refractive errors. The main types of refractive errors most people will experience includes myopia which is nearsightedness, hyperopia or farsightedness, and astigmatism which is when blurred vision is due to irregular cornea shape. Presbyopia is another condition that affects older adults, resulting in difficulty focusing on close objects.
Can Vision Be Corrected with Glasses?
Glasses correct refractive errors by adjusting the way light rays enter our eyes. The science is rooted in the field of optics. Following are the different vision problems and how glasses are used to correct them.
• For Myopia: Concave lenses are used. These lenses are thinner at the center than the edges. When light passes through these lenses, it spreads out or diverges. This helps move the focus point from in front of the retina to directly on the retina.
• For Hyperopia: Convex lenses come to the rescue. They are thicker at the center and thinner at the edges. They make the light rays converge or come together, pushing the focal point back onto the retina when it would otherwise focus behind it.
• For Astigmatism: Cylindrical lenses are used to correct the uneven focusing of light. These lenses have different curvatures in different directions, ensuring light focuses on a single point on the retina.
• For Presbyopia: Bifocals or progressive lenses are the solution. They combine multiple corrective powers in one lens, with distinct areas dedicated to near and distance vision.
How Do Contact Lenses Work?
Contact lenses work using similar principles as glasses, but sits directly on the cornea, making them a bit more complex.
• Soft Lenses: Made from flexible plastics that allow oxygen to pass through to the cornea. They are used to correct myopia, hyperopia, astigmatism, and presbyopia.
• Rigid Gas Permeable (RGP) Lenses: These lenses maintain their shape while on the eye and are used to correct most vision problems. They can provide sharper vision than soft lenses, especially for people with astigmatism.
• Toric Lenses: Specifically designed for astigmatism, they have different powers in various lens levels and can rotate to the proper orientation on the cornea.
• Multifocal Lenses: Like bifocal glasses, they offer different powers in the same lens to correct presbyopia alongside other refractive errors.
Eye Exams, Eyeglasses, Sunglasses, Contact Lenses & More in Delray Beach, FL (Just Minutes Away from Boca Raton, Highland Beach, Kings Point, Golf & Boynton Beach, Florida)
Behind every pair of glasses and pair of contact lenses is a science and engineering wonder. They correct our vision, helping millions worldwide experience the world in sharp detail. For eye exams, prescription glasses, contacts and designer eyewear, contact Eyewear Candy Optical RX today.