The effects of burns vary depending on the depth and size. Superficial or first-degree burns only affect the epidermis, causing pain for a short period of time. Superficial partial-thickness burns cause weeping blisters and require dressing. Deep partial-thickness burns are dry and less painful due to the burning away of the skin and require surgery. Full-thickness or third-degree burns affect the entire dermis and is susceptible to infection. Fourth-degree burns reach deep tissues such as muscles and bones, causing loss of the affected area.Thermal burns are the most common type of burn, caused by contact with excessive heat, including contact with flame, contact with hot surfaces, or scalding burns caused by contact with hot water or steam. Frostbite is a type of burn caused by contact with excessive cold, causing cellular injury and deep tissue damage through the crystallization of water in the tissue. Friction burns are caused by friction with external objects, resulting in a burn and abrasion. Radiation burns are caused by exposure to ionizing radiation. Most radiation burns are sunburns caused by ultraviolet radiation or high exposure to radiation through medical treatments such as repeated radiography or radiation therapy.Electrical burns are caused by contact with electricity as it enters and passes through the body. They are often deeper than other burns, affecting lower tissues as electricity penetrates the skin, and the full extent of electrical burns are often obscured. They will also cause extensive destruction of tissue at the entry and exit points.
For some patients the removal was only performed on one eye, resulting in the anisometropia / aniseikonia. Today, this is rarely a problem because when the lens is removed in cataract surgery, an intraocular lens, or IOL is left in its place.Retinal aniseikonia occur due to forward displacement, stretching or edema of retina. Diagnosis
A way to demonstrate aniseikonia is to hold a near target (e.g., a pen or a finger) approximately 6 inches directly in front of one eye. The person then closes one eye, and then the other. The person should notice that the target appears larger to the eye that it is directly in front of. When this object is viewed with both eyes, it is seen with a small amount of aniseikonia. The principles behind this demonstration are relative distance magnification (closer objects appear larger) and asymmetrical convergence (the target is not an equal distance from each eye). Treatment
Optical aniseikonia due to anisometropia can be corrected by spectacles, contact lenses or refractive corneal surgeries.Spectacle correction is done by changing the optical magnification properties of the auxiliary optics (corrective lenses). The optical magnification properties of spectacle lenses can be adjusted by changing parameters like the base curve, vertex distance, and center thickness. Magnification size matched lenses that are used to correct aniseikonia are known as iseikonic lenses.Contact lenses may also provide less difference in retinal image size. Wider and better field of vision is another benefit of contact lens use.