How do we see?

In order to see clearly, the cornea and the lens directs the rays of light to the retina. The retina transforms the rays of light into impulses, and sends them via the optic nerve to the brain, where the images are recognised. If the rays of light are not focused on the retina, the image seen is fuzzy. This problem is known as a refractive defect. Glasses, contact lenses and refractive surgery all aim to correct refractive defects.
There are different types of refractive defects:

1. Myopia: If your eye is longer than normal, or the cornea and lens have excessive focusing power, the rays of light are focused in front of the retina, instead of on it. This refractive defect means that you have will problems seeing distant objects, which will be blurred.
2. Hypermetropia: If your eye is shorter than normal, or the cornea and lens do not have enough focusing power, the rays of light are focused behind the retina. This refractive defect means that you cannot see near objects clearly.
3. Astigmatism: The curve of the cornea is not uniform – it is more pronounced in one direction than the other, rather like the back of a spoon. This unequal curve means that the rays of light focus on various points of the retina, distorting both near and distant vision.
4. Presbyopia: if you suffer from presbyopia or eyestrain, near objects can seem blurred. Presbyopia habitually appears around 40 years of age, when the lens starts to harden and loses elasticity.

The first step is to have an ophthalmological check-up conducted by a specialist in refractive surgery. This will determine the need and feasibility of laser surgery treatment. Once surgery has been confirmed as the best option, further tests will be conducted in the days immediately prior to surgery, in order to allow the technological equipment to be programmed with precise data. There are different techniques for refractive surgery. In the Gutiérrez Mazeres & Amorós Ophthalmological Centre (COGMA), besides working with a large number of them, we are equipped with the most up-to-date technology on the market. Thus, after the pre-operative study, our team will inform you of the most suitable technique(s) for correcting your refractive defect.

Refractive techniques

Excimer Laser Refractive Surgery, personalised lasik technique

Excimer laser refractive surgery, assisted with femtosecond laser (Femtec), personalised technique.

Refractive surgery with the implantation of flexible intraocular contact lenses (ICL or Toric ICL)

Refractive surgery with the implantation of multi-focal/toric/bifocal intraocular lenses.

Intracorneal lenses

Intracorneal rings

Corneal strengthening surgery, cross-linking technique assisted with femtosecond laser (Femtec®)

Conductive Keratectomy (LTK)
Photo-refractive keratectomy (PRK)
Astigmatic keratectomy (AK) with Femtec ® femtosecond laser