Short, Long Sight & Astigmatism

Karen Brown

Diagram of EyeThe front surface of the eye (cornea) acts as a lens. With perfect sight, the image is brought into sharp focus on the back surface of the eye (retina). Vision problems occur when the image is not accurately focused on the back of the eye and vision is blurred.

The cornea accounts for most of the focusing power of the eye and changing it's shape by tiny amounts corrects focussing problems. Glasses strength is measured in dioptres, expressed as SPH (spherical lens) and CYL if astigmatism is present.

Laser Eye Surgery for Short Sight (Myopia)

Short sight develops through the teens, affecting 25% of the population. If you are short-sighted, the focusing power of your eye is too strong. Objects at a distance appear blurred and close-up vision is clear. Laser surgery reduces the focusing power of the eye by flattening the cornea. Images are then brought into focus. Surgery for Myopia is simple and effective.

Example of a short sight prescription:

Right Eye -2.50 -0.50 120
Left Eye -2.50 -0.50 45
Please note: the dash or minus sign in the sphere (SPH)

Laser Eye Surgery for Astigmatism

Astigmatism occurs when the eye's shape is irregular, like a rugby ball and can be corrected by laser eye surgery.

This condition allows only partial focus on an image, while blurring occurs at all distances. For instance, astigmatism can cause some wheel spokes to appear clearer than others. Astigmatism is shown on your prescription in the box marked CYL and is measured by the strength of a cylindrical lens required for your clearest vision.

AXIS shows the angle at which astigmatism lies across the eye (the spokes which are most blurred). Laser surgery for astigmatism is very effective and is given in the same sitting as your prescription correction and is included in our charges (unlike some companies who charge extra for astigmatism).

Example of an astigmatic prescription:

Right Eye -3.50 -1.50 120
Left Eye -4.00 +2.25 60
Please note: CYL can be measured as plus (+) or minus (-)

Laser Eye Surgery for Long Sight (Hyperopia)

If you are long-sighted, the focusing power of your eyes are too weak. You are able to view objects far away more comfortably than close up (less than 2 m, or six feet). Our new Schwind lasers have proved to be excellent at treating high levels of long sight, far beyond most other lasers in the market.

Right Eye +2.00 -0.50 120
Left Eye -4.00 +2.25 60
Please note: the plus (+) sign for the sphere (SPH)

Reading Glasses (Presbyopia)

Presbyopia is the age-related need for reading glasses which comes to us all. There are several options to treat the need for reading glasses which will be discussed on your consultation. Youthful vision can be restored by the following methods:

Lens Surgery
Click here to read more about Lens Surgery

Monovision is where one eye is corrected for near vision and the other for far distances. Many people already enjoy Monovision by wearing an underpowered contact lens in one eye. This can be reproduced by laser surgery.
Click here to read more about Monovision

Presbymax, multifocal laser surgery
Click here to read more about Presbymax
Short sighted people can remove their glasses to read and for close up work. As with all normal sighted people, if you have laser surgery to fully correct your distance vision, you will need reading glasses from the age of about 50 (unless you choose one of the above options).