Corrective lenses: the go-to treatment for optometrists when diagnosing a patient with refractive errors.
Everyone with some form of vision problem has likely worn a pair of corrective lenses once or twice in their lifetime. If you haven’t worn them already, it is almost guaranteed you will as you age and develop presbyopia.
So, since everyone will have to use them eventually, it wouldn’t hurt to know a little more about them, right? Right.
How do Corrective Lenses Work?
Corrective lenses are designed to help your eyes focus incoming light directly onto the retina, thus producing clear vision. They work by acting as the first surface light rays hit, therefore properly bending the light rays to the degree required by your given condition.
Our optometrist will prescribe you corrective lenses based on the degree in which light rays will be bent, measured in diopters. A general rule of thumb is the greater need for bending light results in a higher prescription, as well as thicker lenses.
Hyperopia
Hyperopia causes incoming light rays to focus beyond the retina due to a shortened eyeball. To correct it, convex lenses are prescribed to reduce the distance in which the light will travel to accurately focus it on the retina.
Myopia
A refractive error that causes incoming light to focus in front of the retina as a result of an elongated eyeball. To correct it, our optometrist will prescribe concave lenses the increase the distance in which the light will travel to focus it on the retina. Essentially, these lenses will do the opposite of what a prescription for hyperopia will do.
Astigmatism
Astigmatism is a refractive error that causes light to focus in multiple points, causing blurred vision at any distance. In order to correct it, the use of cylinder lenses is required to create multiple focus points. This will allow the image to land on one single point instead of in multiple locations.
Presbyopia
Two types of prescription lenses work to correct presbyopia: monovision or multifocal lenses. Monovision lenses correct your distance vision on one eye, while correcting your near vision in the other eye. Multifocal lenses, however, are lenses that correct multiple distances by the top half correcting distance, and the bottom correcting nearby.
Types of Corrective Lenses
Corrective lenses come in three main types: glasses, contacts and intraocular lenses.
- Glasses. The most common form of correct lenses. Glasses come in many different types, such as: monofocal, bifocal, trifocal, progressive lenses, adjustable lenses, and more.
- Contact Lenses. Growing in popularity, contact lenses are a form of corrective lenses that have become most patients preference as they are more comfortable and don’t require a foreign body to rest on your nose. Like glasses, contact lenses come in many different types, such as: disposable, daily wear, extended wear, bifocal, rigid gas permeable, toric, and more. Each type of contact lenses has its own unique uses.
- Intraocular Lenses. Most commonly used to replace the eye’s natural lens that has been removed due to cataracts or glaucoma, intraocular lenses are implanted into the eyeball. Majority of these corrective lenses are monofocal, allowing the user to only see the distance in which they were designed for.
Looking For More?
If you’re still curious about learning more regarding corrective lenses, book an appointment with our optometrist. While you’re at it, why not have a comprehensive eye examination? To your surprise, we may discover an unidentified vision problem preventing you from seeing the best you possibly can.
