Reducing the Need for Glasses and Contact Lenses
Why do I need to wear glasses or contact lenses?
There are a number of conditions which can make our vision blurred that are corrected by wearing glasses or contact lenses. Depending on the type of condition, you may have trouble seeing objects at a distance from you, close to you, or both. The conditions that cause these problems are:
- Myopia (Short sightedness)
- Hyperopia (Long sightedness)
Myopia is one of the common conditions that causes people to have trouble seeing objects in the distance but have no problems seeing objects close to them. It is also called short sightedness. Activities that many people with myopia find difficult without wearing glasses or contact lenses are driving a car, watching TV or playing sports.
Myopia is caused by the eyeball growing too long or in some cases, the curvature of the cornea (the clear window at the front of the eye) being too steep.
Hyperopia is another common eye condition which causes people to have difficulty focusing on objects close to them but have less of a problem seeing things far away. This condition is also known as long sightedness. As people with hyperopia become older, they often also have increased difficulty seeing objects at a distance as well as up close. This causes people to need glasses or contact lenses for both reading as well as seeing things at a distance from them.
Hyperopia is caused by the eyeball being too short or in some cases, the curvature of the cornea (the clear window at the front of the eye) being too flat.
Astigmatism is a condition where objects at both distance and near appear blurred. It is caused by the cornea (the clear window at the front of the eye) not being a perfect spherical shape. An eye without any astigmatism has a cornea that is shaped like half a soccer ball. An eye with astigmatism is shaped more like half a rugby or AFl ball. When the cornea is not spherical, the light entering the eye is not focussed precisely and results in vision being blurred at all distances. When astigmatism is mild however, people generally only notice that the distance vision is blurred.
Presbyopia is a result of changes that happen within our eye as we age. When we are younger, the lens within our eye is flexible. This allows it to change its shape which is how we are able to change our focus from something in the distance to something close to us. As we age, the lens becomes less flexible and as a result, things closer to us become harder to bring into focus.
The first signs of presbyopia are needing to move a book, magazine or computer tablet further away from you to make it appear clear. Often people will make the comment ‘my arms aren’t long enough anymore’ when presbyopia is starting to affect their close vision more significantly.
For all of the conditions mentioned above, the use of glasses or contact lenses will almost always provide clear vision. For people who would like to reduce or eliminate their need for glasses and contact lenses, there are now many options available. The most appropriate option depends on many factors including the type of condition, the health of the eye, the shape and thickness of the cornea and the age of the patient. A consultation with one of our experienced Ophthalmologists will allow the best option to be selected with you.
In general the surgical options are:
Laser Refractive Surgery
This procedure involves reshaping the surface of the eye, the cornea and is best suited to treating myopia and astigmatism however it can be used for other conditions. There are many types of laser refractive procedures which suit different eye types and conditions. Examples of laser refractive procedures are:
LASIK – Laser Assisted Laser-Assisted In-Situ Keratomileusis
PRK – Photorefractive Keratectomy
Lensectomy or Refractive Lens Exchange
This procedure involves removing the lens inside the eye and replacing it with a different artificial lens. The procedure is almost identical to cataract surgery. The lens that is inserted is calculated and selected to correct the glasses or contact lens error of the eye. A lensectomy or refractive lens exchange is the more common way to reduce or eliminate the need for glasses in patients who are aged approximately 50 years or older.
There are many lens options that can be implanted to improve your vision. Some options are:
- Multifocal intraocular lenses
- Recent advances in lens technology have led to the development of these excellent lenses
- Patients typically achieve 90% spectacle independence and this will give you the ability to see clearly at both distance and near without glasses.
- Side effects of these lenses can include halos around lights at night and mild loss of contrast
- Multifocal intraocular lenses
These lenses are not ideal for people with high visual demands or that do a lot of night time driving.
- Both eyes distance focus
- The lens for each eye is customised to minimise any near or long sightedness and astigmatism and provide clear focus for distance objects
- If you choose this you will have no or minimal need for distance glasses but will need to wear reading glasses
- One eye distance, one eye near (monovision)
- While this sounds like it would confuse your brain, 80% of people adapt to it very well and achieve excellent results
- Typically people still need a pair of reading glasses for very fine print.
- Side effects of this choice can include a mild loss of depth perception.
- Both eyes near focus
- This is the most common choice for people who have been short sighted all their life
- With this choice you will have minimal need for reading glasses, but you will need to wear distance glasses
Implantable Contact Lens
This procedure involves implanting a small lens inside your eye which contains a similar strength prescription to your glasses or contact lenses. This results in a clear vision and is especially useful for patients with very high glasses or contact lens prescriptions or irregular eyes which cannot undergo laser refractive surgery. Implantable contact lenses can also be removed if required.