As we get older (beyond the age of 40) the LENS in our eye becomes larger and harder and less able to change shape. The lens is used to fine focus and enable us to read in earlier life. The ability to do this decreases over time and we then require reading glasses. Presently Laser eye surgery does not correct presbyopia accurately and predictably and is not offered at Centre for Sight. However often patients in their 40s or older are able to read following laser eye surgery and this can be for many reasons, including mild residual shortsightedness or a multifocal cornea. Another option is Monovision or “Blended vision” where one eye (the non-dominant) is purposely made a little shortsighted to enable reading. We do offer this treatment in those who are already wearing Monovision contact lenses. We do not offer this routinely as patients often find monovision / blended vision difficult to get used to and often unhappy having one eye seeing very well at distance and the other (reading eye) blurred.

This is where an eye has not developed properly. Amblyopia occurs because one eye has not had good vision in childhood. The brain shuts down receiving stimulation from that eye as the information being provided is confusing. As this has shut down, the brain just does not develop the necessary connections in order to interpret information from that eye. The most common cause of amblyopia is refractive error and in particular a difference in error between the two eyes. Children who are farsighted(hyperopic) or who have high amounts of astigmatism are at higher risk. Often the amblyopic eye develops a squint or eye turn.

It is therefore important that ALL children have eye tests periodically and if they develop a squint, they should be seen by an ophthalmologist without delay.

The most common cause of visual field loss is Glaucoma. Glaucoma is also known as the “sneak thief” of sight. It takes vision away gradually and in a manner that is not easily picked up except by specific testing. A Visual field test is used to monitor vision of patients, in particular those with glaucoma or a family history. The visual loss in glaucoma affects the periphery with gradual loss from the outside inwards (so called “tunnel vision”) Visual loss in reality takes place in steps, initially with reduced ability to see followed later by absolute loss. These defects are “relative” if they are reduced or “absolute” if lost totally. The Visual Field Test can be a long and tedious test, however is vital for monitoring.

Age Related Macular Degeneration can also cause a visual field loss and this can be central – in the middle of the field of view. Patients often report being able to see objects from the side, however as soon as they look directly at the object it disappears. This is a central field defect which can be extremely debilitating. This type of defect can be preceded by the observation that straight lines do not seem straight anymore. If this occurs or if there is a sudden loss of vision, then this is considered an emergency and the patient must be seen by an ophthalmologist immediately or present themselves to an eye casualty. There are number of newer treatments that may be able to help in the early stages of this condition.