Millions of people with poor eyesight worldwide are turning to contact lenses to correct their vision. Compared to glasses, contact lenses provide better vision, especially to the sides of the user. Many users also prefer contact lenses for aesthetic or practical reasons.
Contact lenses are classified into two general kinds: hard and soft. While soft contacts are more popular nowadays, there are some users who prefer hard lenses. This article will discuss the differences between the two kinds of contacts.
The first contact lenses were hard contacts. While their original material was blown glass, they were gradually replaced with contacts made from polymethyl methacrylate (also known as Plexiglass). The first non-glass hard contact lenses let very little oxygen into the cornea, which resulted in serious side effects in their users. Newer hard contact lenses, made from oxygen-permeable polymers such as fluorosilicone acrylate, let oxygen in. The new materials also allow users to wear hard contacts for long periods in demanding environments, such as high heat or humidity.
Hard contact lenses work by covering the natural shape of the cornea with a corrected refracting surface. Thus, they can correct for astigmatism and are also recommended for patients with corneal abnormalities such as keratoconus. Patients recovering from eye surgery also benefit from wearing hard contact lenses to protect their corneas. However, many patients experience a bit of discomfort upon starting the use of hard contact lenses.
First introduced in the late 1960s, soft contacts are popular throughout the world. Most soft contact lenses distributed now are composed of silicone hydrogels. These soft contacts combine the comfort of hydrogels and the oxygen permeability of silicone. Most brands offer soft contacts for extended wear; that is, up to 30 days of use in normal environments.
Ophthalmologists prescribe soft contact lenses for correcting visual impairments, such as dry eyes, myopia, and corneal abrasion. Because they are far easier to wear, many people with otherwise healthy vision use soft contact lenses for aesthetic reasons. With proper care, a person wearing soft contact lenses will feel very little, if any, discomfort.
Hard vs Soft Contacts
What are the differences between hard and soft contacts? Their major differences lie in the materials used in the manufacture, their durability, usage, and their users’ comfort level.
Most hard contacts are made from rigid yet oxygen-permeable polymers such as fluorosilicone acrylate. In contrast, most soft contact lenses available today contain silicone hydrogel.
Thanks to their more sturdy material, hard contact lenses see heavy use in more demanding environments. Many hard contacts last up to five years with regular cleaning and care. Meanwhile, soft contact lenses need replacement every four weeks, with many brands offering variants authorized for up to six months’ use.
The rigidity of hard contacts allow them to be used in cases where corrected refraction is required, such as keratoconus or astigmatism. They also protect eyeballs and corneas from being bruised and are typically worn by those recovering from an eye surgery such as LASIK. Soft contacts, on the other hand, have heavy use among people with visual impairments such as dry eyes, issues with color perception, and myopia. Many people also use soft contact lenses for aesthetic purposes, such as changing their eye color.
While newer models allow the eyes to “breathe,” hard contact lenses often result in discomfort for first-time users. Soft contact lenses offer a more comfortable feeling on the eye, leading to their recent popularity.
|Hard Contacts||Soft Contacts|
|Made of fluorosilicone acrylate||Made of silicone hydrogel|
|Last up to five years||Last up to six months|
|Prescribed for correcting refraction; protecting eyes post-surgery||Prescribed for vision correction; color perception; aesthetic purposes|
|Relatively uncomfortable||More comfortable|