Myopia (Short Sightedness)
This is the name given when the image does not reach the retina and actually falls short of it (or in front of it).
This happens when the eye is too long for the focusing power of the cornea and the lens.
Light rays bend more than they should, so they focus in front of the retina.
The optician’s prescriptions will show a minus sign before the number called ‘Sphere’ (e.g -2.00D). The larger number, the more short sighted the eye and the further in front of the retina the image will fall.
A person who is short sighted would be able to see objects at close range, but distance and even mid-range objects would be blurred.
If the eye is too short for the refractive power of the cornea and lens, the image produced will be focused beyond the retina.
Light rays bend less than they should, so the focused image lies behind the retina.
Hyperopia (Long sightedness)
Astigmatism is caused by irregularities in the curvature of the parts of the eye responsible for focusing light rays (the cornea and the lens).
An even curve (a round eye) results in even focusing of the light rays making up and image that will be clear.
if the curvature of the eye is uneven (rugby ball shaped), light rays bend at different angles, so they are not all focused at the same spot, causing blurred images at distance and at near.
Astigmatism
Presbyopia
From the age of 40, it is common for people to wear reading glasses.
This is due to the natural lens in the eye becoming less flexible. As a result, objects near to the eye become more blurred as the natural lens cannot change its shape as much.
People tend to hold their print further away to read and eventually, reading glasses, bifocals or vari-focals are needed.
Long sighted people may be affected at a younger age than short sighted people who may benefit for a short period by being able to read without spectacles.
Keratoconus is a non-inflammatory eye condition in which the normally round dome-shaped clear window of the eye (cornea) progressively thins causing a cone-like bulge to develop. This eventually impairs the ability of the eye to focus properly, potentially causing poor vision.
Kerataconus (Corneal ectasia)
Cornel scaring makes the surface of the eye irregular, meaning light rays cannot pass effectively into the eye. Small scars often do not cause significant visual problems and can heal naturally over time. However, some scars can result in the loss of vision, and there are opportunities to treat this with either laser treatment, or in more advanced cases corneal transplantation. This is something that can be discussed in depth at your appointment.
Corneal Scarring
Recurrent corneal erosion syndrome causes significant pain and can become a major burden on the quality of life of some patients. This is usually caused by the outermost layer of the surface of the eye becoming poorly attached to the layer below, meaning this layer can become slippy and break down easily. This can cause significant pain and discomfort in some patients.
Many cases can be treated medically with drops. Some patients require more advanced treatments in the form of phototherapeutic laser treatment. This helps to reshape the surface of the eye and can help make this adhere better to layer below.
A series of diagnostic tests need to be taken to determine if you are suitable for this treatment.
Recurrent Erosions