This can occur in all types of vision – distance, near or even both. Astigmatism is when the cornea is not perfectly spherical and can occur in long or short sighted eyes. With astigmatism, an object will look out of focus by different amounts – for example, the letter X will look distorted at different points. Astigmatism can be corrected by glasses or contact lenses. Different powers within the lens are arranged specifically to correct this error of vision.
This is the term used for the reduced ability to focus on near objects. This usually occurs in the forty- plus age group and is the result of less flexibility in the lens of the eye. This is normally an age related process and results in the majority of people requiring help from reading glasses. Presbyopia can be easily corrected using either reading glasses, or varifocals – even available as contact lenses.
As we get older, the lens within the eye will change – this is normal. In most people the vision becomes less clear as not enough light is able to get through to the retina; this loss of clarity is due to opaque areas (Cataracts) which can affect our everyday life depending on how dense they are. Cataracts can be caused by a number of reasons: injury, UltraViolet exposure and some medicines, but they are mostly age related. By the age of 70 most people will have developed them to a certain extent. Cataracts can be removed surgically and replaced with a plastic lens, generally requiring patients to attend hospital for half a day. Success rates are high and surgery will greatly enhance post operative vision.
Glaucoma is a condition in which the optic nerve can be damaged by an increase in pressure within the eye. The optic nerve is like an electric cable containing about 1.2 million wires. Glaucoma can damage nerve fibres, causing blind spots on the retina to develop. Glaucoma can be hereditary and currently the NHS will pay for a regular eye examination for anyone who is over 40 and has a parent, brother, sister or child who has had, or is suffering from glaucoma.
This condition results when the body is unable to use and store sugar properly. High levels of sugar or glucose in the blood damage the delicate blood vessels in the retina. This condition is referred to as diabetic retinopathy. Approximately one quarter of all diabetics have some degree of retinopathy. The prevalence of diabetic retinopathy increases with the duration of diabetes. More than 90% of diabetics will develop retinopathy at some point during their lives.
The macula is a small area at the centre of the retina. It is responsible for what we see straight in front of us, allowing us to see fine detail for activities such as reading and writing, as well as the ability to see colour. As we age, the macula can ‘wear out’ – this is known as Macular Degeneration. Peripheral vision is mostly unaffected; however, the concentrated central vision can deteriorate gradually. An initial sign that macular degeneration may be occurring is when straight lines appear bent and symmetrical objects appear misshapen. Eventually a ‘black hole’ can develop in the centre of the vision causing difficulty with every day tasks. In most cases, treatment is limited, whether by using high power magnifiers or specially tinted lenses. If you would like to know more about macular degeneration please visit the following sites: www.rnib.org.uk and www.maculardisease.org.
Our eyes contain a jelly-like fluid called the Vitreous Humour. Floaters are particles suspended within the vitreous humour and are commonly more noticeable with age – appearing like flies or spiders in your line of sight. It is recommended that any person noticing the sudden appearance of a large number of floaters should make an appointment to see our team of Ophthalmologist or Optometrist as soon as possible.
The front surface of our eye is covered by a thin film called the ‘tear film’ – which covers the cornea, iris and the sclera (the white part of the eye). Its function is to maintain a smooth surface, reduce friction when blinking and protect the eye from infections. The tear film is very sensitive and any slight change in its consistency can cause irritation. These changes can be brought about by factors such as allergies, air conditioning, illness and some medications. Dry eyes are more common with older patients and contact lens wearers and can often be easily corrected by using artificial tear drops. Your optician may discuss with you about changing the type of contact lenses you wear.