Why do we need glasses or contact lenses?

The reason why people need to wear glasses or contact lenses is because there is a problem or an imbalance in the focusing power of the eye.

Patients who are short-sighted or myopic have too much focusing power, so they need to wear a negative power lens in front of the eye in order to bring the image of the world into focus on the retina.

Patients who are long-sighted, do not have enough focusing, so in order to bring the world into focus on the retina, they need to wear a plus lens in front of the eye.

Lastly, astigmatism is a condition where the eye rather than being completely circular has an oval shape to it and this requires an oval shaped or what is called a toric lens to be worn in front of the eye to bring the world into focus.

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About the author

Mr Alex J. Shortt | Consultant Ophthalmic Surgeon

MB BCh MSc PhD FRCOphth PGDipCatRef

I’m Alex Shortt, a highly trained academic researcher and Consultant Ophthalmic Surgeon based in London’s famous Harley Street medical district. I trained and worked as a consultant for 14 years at London’s Moorfields Eye Hospital. I specialise in advanced technologies for correcting vision, including cataract surgery, implantable contact lenses and laser vision correction.