Difference Between a Hard and Soft contact lens
Before explaining the difference between the hard and soft contact lens i want to elaborate about the category of lenses. Contact Lenses come in two main categories
HARD contact lens
- soft contact lens
Hard contact lenses are further subdivided into two main categories.
RGP & SCLERALS.
I will try and explain the main differences between the hard and soft contact lens. i will also show where we can apply the best.This will hopefully help patients decide which type of lens suits their needs best.
In many cases, two or three choices will work just as well. The final choice is depends on the the need and affordability.
cost effective and/or frequency of wearing it
difference between the hard and soft contact lens
- soft contact lens
Soft contact lens are mass produced.one size fits all lenses which make up over 90% of all contact lens sales worldwide. you can easily and quickly fit in to your eyes. it cover the most popular powers. these are available for short-sightedness, far-sightedness, astigmatism and varifocals for people over 40.
- You can also get them in various colours. They either last for 1 day or 1 month. The reason why they take up most of the market share is because we can easily fit them.
- generally it is very comfortable and we need to spend a minimum time in the consulting room to fit them.
- They aren’t available in all powers. so people with higher spectacle prescriptions would need to consider hard lenses. They also have the highest risk of infections and ulcers.it was problem especially if not cleaned properly.
- HARD contact lenses
- HARD contact lenses have custom designed. you can also easily fit it into your eyes.so technically anyone can have them. But because they take longer and are more difficult to fit, it would not be practical to give everyone hard lenses; instead we reserve them for people who have no other options.
- The majority of hard lens patients are those with some problem that results in an uneven corneal surface (the front surface of the eye). Examples are Keratoconus, corneal grafts, corneal injuries, Steven Johnson Syndrome etc.
- Other examples of ideal hard lens candidates are healthy corneas with high prescriptions, and ex-soft contact lens patients who developed problems from either allergy/dryness or overwear
- RGP (stands for Rigid Gas Permeable)
- RGP ( Rigid Gas Permeable) is the first category of hard contact lenses and have been around for many decades. They can be uncomfortable, especially if not fitted perfectly. They also feel much worse with a dry eye and can pop out easily.
- so they aren’t ideal for many activities. Having said that, many people are still happily wearing their hard lenses today
- SCLERAL lenses
- Scleral lenses are the second category of hard contact lenses. thses lenses are indicated when you are not able to tolerate hard contact lens anymore.
- it may either due to dryness or when the shape of the cornea has regressed so much that the lens can’t stay in the eye. This happens in advanced Keratoconus. They are also sometimes the first choice of lens because of their comfort.
- Unlike all other contact lenses (soft & hard included), Sclerals don’t float on a layer of tears.it rest on the white part of the eye (called the Sclera). By doing so, they seal a layer of fluid between the lens and cornea.so the eye stays moist all day long, even extreme conditions like air conditioned rooms, underground in mines, smoky environments etc.
In conclusion, a contact lens practitioner will help you decide which lens is best for you as an individual. Even with professional advice, you will only find the best lens after 2 or more attempts.but it is a lifelong choice so worth the effort. As long as you have clear, comfortable vision, and are not restricted in your activities you will know what works for you.