Personalised Laser Eye Surgery

Your Prescription

You have a prescription or refractive error if the light entering your eye does not fall as a pinpoint on the retina. The majority of us have a refractive error of some form, even if very small.

The Normal Eye

The eye shown in this diagram has no refractive error; or prescription. In life, only a small percentage of us are so perfectly formed! Here light is focused perfectly at the focal point on the retina at the back of the eye.

Myopia (short-sighted):

In this second diagram the eye is myopic or short sighted. Many of us have this type of refractive error. Here images in the distance will appear blurred and those close to us will be clear. The extent of this will depend on the level of myopia present.

Images are blurred because the light rays cross before they hit the focal point, as the cornea (clear covering at the front of the eye) is too steep. The term short sighted is used because the light focuses short of the retina. In laser treatment we gently flatten the cornea to move the focal point back onto the retina.

Mypoia is represented by a minus sign (-) on your prescription.

See Am I suitable? for the prescription range treatable at Advance VisionCare.

Hyperopia (long- sighted):

In this diagram the eye is hyperopic or long-sighted. This is effectively the opposite to myopia as the light is focused too long for the retina. Images are blurred because the light rays effectively cross after they hit the focal point, as the cornea is too flat. In laser treatment we gently steepen the cornea to move the focal point onto the retina.

Hyperopia is represented by a plus sign (+) on your prescription.

See Am I suitable? for the prescription range treatable at Advance VisionCare.

Astigmatism (distortion)

In this diagram the eye has astigmatism, where some rays of light are focused in different positions to others, creating a distorting effect. This is because the cornea is not a perfect sphere, but rather eliptoid. A popular analogy is that the cornea is shaped more like a 'rugby ball' instead of 'football'.

Most of us have some degree of astigmatism combined with our myopia or hyperopia. In laser treatment we gently smooth away these irregularities to bring the focal point back to the retina.

See Am I suitable? for the prescription range treatable at Advance VisionCare.

Presbyopia (Age related reading focus)

When we get to the age of approximately 45, we begin to find it difficult to focus on reading, and start to require the aid of reading glasses for close work and reading. This is because it becomes difficult for the lens inside the eye to change shape, and therefore alter our ability to switch from distance to near vision. If you are at this age or above and require glasses for near vision, you are presbyopic.

Laser Eye Treatment cannot correct presbyopia but at Advance VisionCare we now offer treatment for this condition called Conductive Keratoplasty that can eliminate the need for reading glasses.

Higher Order Aberrations (tiny imperfections)

In addition to our refractive error, many of us also have higher order aberrations or imperfections in our eyes, which are not correctable by spectacles or contact lenses. These are created by the tiny irregularities in the biological structures of our eyes.

At Advance VisionCare we use the latest wavefront treatment to treat these aberrations where possible, to give the patient a better quality of vision post-operatively

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Advance VisionCare | 77 Harley Street | London | W1G 8QN
Tel: 0800 652 4878