girl with glasses

What is the Spectacle Free Zone?


Vision is like any biometric measurement, there is a range of normal rather than one single measurement. Google says that the average height of men in 1.7meters. That does not mean that anyone who is taller or shorter is abnormal, there is a range within which most of us are. The range of spectacle free vision is described in this article. The numbers are the lenses needed to put the eye into “perfect” focus. Someone whose focus is at point X has a spectacle prescription of -0.50 of myopia and 0.25 of astigmatism.

Wearing a weak prescription would theoretically give the person better vision but in practice it’s so weak that nobody would bother wearing such a pair of glasses. Such people regard themselves as spectacle free. Anyone whose spectacle prescription falls in the blue zone would regard themselves as spectacle free and can see the world without glasses just as well as anyone else. They can perform all visual tasks perfectly with no glasses or contacts. You will notice that there is no sharp edge to the zone but rather there is a gradual transition into the zone were glasses are necessary to see clearly. The purpose of laser refractive surgery is to move your vision from the zone where glasses are necessary into the zone of spectacle free vision. We do not need to get you to the very centre of the zone to be successful. This is where the brain comes in.

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Think of good vision as 20% optics (focus) and 80% data processing.

If the visual cortex gets an image from within the zone it will process it so that it will appear to come from the very centre. That is perfect vision. The software the brain uses to analyse vision is designed to work with eyes that are focused in the spectacle free zone. Evolution demanded this. That’s why we say that glasses, and to a lesser extent contacts, do not solve the problems of ametropia. They just make it survivable. Laser refractive surgery gives you the vision nature intended you to have. Laser vision correction is not a luxury; it’s a release from a handicap, the correction of a blemish.

About Our London Eye Clinic Experts

Meet the My-iClinic founders, Mr John Bolger and Ms Bola Odufuwa. Two consultant eye surgeons who made it their life goal to make your life better.

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Bola Odufuwa-Bolger

Consultant Ophthalmologist
Clinic Director

Bola Odufuwa is a consultant ophthalmologist at The Royal Free Hospital and My-iClinic. Her specialities include cataract, glaucoma, paediatric, and laser refractive surgery. Bola has had extensive training at Moorfields Eye Hospital, London, where she gained expertise in the management of various eye conditions.

Bola Odufuwa’s special interests include optimal refractive outcomes following cataract surgery, non-penetrating glaucoma surgery, and assessment eyesight in children with special needs: particularly dyslexia and autism.

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Mr John Bolger

Consultant Ophthalmologist
Clinic Director

John Bolger is a Consultant Ophthalmologist and Clinic Director at My-iClinic. His specialities include ophthalmology, laser refractive surgery (SMILE, Presbyond, LASIK, PRK, PTK), refractive lens exchange (RLE), cataract surgery, glaucoma treatment and macular degeneration.

Over the course of his career, John Bolger has carried out over 35,000 cataract operations, 20 of which were for eye surgeons. He has also taught over 1500 young ophthalmologists worldwide as they begin their surgical careers.