Doctor insights on:
Pachymetry: Corneal thickness which plays a role in several diseases of the eye, is measured currently with device termed a pachymeter. This uses a timed pulse of ultrasound which reflects off the top and bottom layers of the cornea which then is computed for that time to produce a digital readout of the corneal thickness.
Cornea v. lens: Clouding of the natural lens (cataract) can be surgically correct with removal of the clouded lens and substitution of an intraocular lens. A cloudy cornea, which has many possible causes, can frequenly be improved with certain medications or corneal surgery such as a corneal transplantation.
Alter eye power: Corneal rings are implanted arcs of plastic into the inner layers of the cornea. They cause a change in the refraction which neutralizes moderate degrees of myopia. They also have some use in moderate keratoconus to improve the vision and some feel to slow the progression. Your corneal specialist ophthalmologist can help with this.
See below: It is the clear tissue in the front of the eye that helps focus light (along with the lens inside the eye) onto the retina (the back wall of the inside of the eye) that senses this light (image) and sends a signal to the brain via the optic nerve for the perception of sight.See 1 more doctor answer
Corneal opacities: Corneal opacities can be cause by anything that injuries the cornea or causes scarring of the cornea. Foreign bodies in the eye are common causes, late effects of severe trauma, various infections, certain congenital or genetic conditions. The image below shows you what one kind of opacity looks like. Do a google search under 'images' for corneal opacity and you will see lots.
Welder's burns: These are ultraviolet light 'sunburns' of the cornea which all welder's know about. The pain of them starts 4-8 hours after exposure and can be quite severe but usually is gone within 24 hours as new corneal cells regenerate. This is why welder's wear those protective filtering masks.
Refraction: Light is bent when it passes from one medium of a certain density to another of a different density. In the case of the cornea, it is passing from air, through the clear cornea which acts like a lens, focusing the incoming light signficantly. It is further bent by the lens inside the eye and hopefully will focus perfectly on the retina at the back of the eye for best vision.
Short time interval: A corneal abrasion is the loss of the overlying skin on the cornea, the window that lets light into the front of the eye. They are usually quite painful. Your ophthalmologist should see this, and may use eyedrops, a therapeutic contact lense and sometimes patching. Healing is usually rapid in 1-2 days unless there is a problem. Try not to treat this yourself.
Depends: This depends on the cause of the scratch. If it is still bothersome after a day or so then you should see your eye doctor. They will likely place you on drops to prevent infection, minimize dryness and and speed healing, these should heal reltively rapidly.