Eye Conditions

To understand which laser eye surgery is best, you need to know how your eyes work.

How do the eyes work?

Normal vision (emmetropia). The human eye is truly remarkable in its design. Vision quality is largely determined by the size and shape of our eyes. In order to see clearly, all the light rays entering the eye must come into focus on a single point on the retina. In a healthy normal eye (emmetropia: no refractive error), all the rays of light entering the eye focus onto the retina without glasses, hence forming a shape and clear image for the brain to see. Check my company. When the eye’s dimensions are not well-aligned, the light rays are not correctly focused on the retina. This results in a refractive error such as near-sightedness, farsightedness and astigmatism. Refractive errors are very widespread and affect people of all ages.
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What is Myopia or near-sightedness?

Myopia occurs when the eyeball is too long. As a result, parallel rays of light come into focus in front of the retina. People with myopia can see objects that are closer to them more clearly, but distant objects are blurred. They may, for example, have difficulty seeing detail on the TV screen and will not be able to drive without wearing their glasses. The longer the eyeball is the higher the glasses prescription would be. People who are short-sighted get a concave (minus) lenses on their glasses which diverges the light and help focus it back onto the retina rather than in front of the retina.

Myopia or near-sightedness

What is Long-sightedness or Hyperopia?

Long-sightedness or Hyperopia

Hyperopia (long-sightedness) occurs when the eyeball is short. As a result parallel rays of light come into focus behind the retina when the eye is in an unaccommodated state. In younger people with long-sightedness, the lens is still flexible and is able to change its shape to accommodate and focus the rays of light on to the retina, providing clear vision without glasses. This however exposes the eye to stress due to the need for constant use of the eye muscle (accommodation), sometimes leading to eye fatigue and headaches. As the natural lens stiffens with age, patients with long-sightedness are no longer able to accommodate and become more dependent on glasses or contact lenses. Patients with hyperopia wear convex (plus) lenses which makes the light rays to converge and hence focus on the retina rather than behind it.

What is an Astigmatism?

This is caused by an irregularly shaped cornea or lens. Normally, the cornea has a symmetrically round shape and curves equally in all directions (like a football). In a person with astigmatism, the cornea is shaped more like a rugby ball, which is more curved one direction (vertically) than the other direction (horizontally). As a consequence, in an eye with astigmatism, light does not come into focus at a single point, instead, there is more than one focal point. For example, in simple (regular) astigmatism, some light rays are brought into focus in front of the retina and some are behind it.

What is irregular astigmatism?

This usually only occurs after getting a disease on the cornea or following an injury to the eye. Glasses or contact lenses may not be able to correct the vision. This can occur in patients with advanced keratoconus. Dr. Arbabi offers different cutting-edge treatment which may help to regularise your cornea and improve your eyesight.

What is Presbyopia?

This is a normal, age-related condition which typically starts to occur after 40 years of age. It’s the reason most people need reading glasses after this age, even if they have never needed glasses before.

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This is because the natural lens of the eye becomes stiffer and loses its flexibility to change its focusing power. In younger patients, the lens is able to increase focussing power (accommodate), to see near objects clearly, and these patients only need glasses for distance. However, presbyopic individuals require bifocals/varifocal glasses or two separate glasses to see near and distance clearly.

Patients who have laser eye surgery may have, or will eventually, develop presbyopia as the normal ageing process.

Options to treat presbyopia are:



This could be bifocal, varifocal or separate reading and distance glasses.
contact lenses

Contact lens

This can be multifocal contact lenses, monovision with contact lens or wearing contact lens and glasses.

Private and NHS roles

Refractive Lens Exchange, other types of LASIK laser eye surgery, conventional monovision surgery or intracorneal inlays.

What is Keratoconus

Keratoconus is a condition that can result in thinning and weakening of the cornea. The disease often starts in late teens or early twenties and gradually progresses before eventually stabilising. In some people the progression can be very severe causing bulging and scaring of the cornea. This may cause blurry vision, double vision and light sensitivity. It occurs in approximately 1 in 2,000 people in the general population. If the disease is stabilised in its early course the vision can be corrected with glasses or contact lenses. As the disease worsens special contact lenses may be required. In very advanced cases other surgeries such as keraring or even corneal transplant may be required to improve vision.
If you have keratoconus it is imperative you are regularly monitored for signs of progression until you are 35 years of age. This is the age when progression is less likely but may still rarely occur. If there was any sign of progression, then a treatment called corneal cross linking is highly effective in stopping the progression of the disease.

Discover the freedom from glasses or contact lenses

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