Photokeratitis or ultraviolet keratitis is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet (UV) rays from either natural (e.g. intense sunlight) or artificial (e.g. the electric arc during welding) sources. Photokeratitis is akin to a sunburn of the cornea and conjunctiva. The injury may be prevented by wearing eye protection that blocks most of the ultraviolet radiation, such as welding goggles with the proper filters, a welders helmet, sunglasses rated for sufficient UV protection, or appropriate snow goggles. The condition is usually managed by removal from the source of ultraviolet radiation, covering the corneas, and administration of pain relief. Photokeratitis is known by a number of different terms including: snow blindness, arc eye, welders flash, bake eyes, corneal flash burns, flash burns, niphablepsia, or keratoconjunctivitis photoelectrica. Signs and symptoms
Common symptoms include pain, intense tears, eyelid twitching, discomfort from bright light, and constricted pupils. Cause
Any intense exposure to UV light can lead to photokeratitis. In 2010, the Department of Optometry at the Dublin Institute of Technology published that the threshold for photokeratitis is 0.12 J/m2. (Prior to this, in 1975, the Division of Biological Effects at the US Bureau of Radiological Health had published that the human threshold for photokeratitis is 50 J/m2.) Common causes include welding with failure to use adequate eye protection such as an appropriate welding helmet or welding goggles. This is termed arc eye, while photokeratitis caused by exposure to sunlight reflected from ice and snow, particularly at elevation, is commonly called snow blindness.
Retrobulbar bleeding, also known as retrobulbar hemorrhage, is when bleeding occurs behind the eye. Symptoms may include pain, bruising around the eye, the eye bulging outwards, vomiting, and vision loss.Retrobulbar bleeding can occur as a result of trauma to the eye, surgery to the eye, blood thinners, or an arteriovenous malformation.In those with significant symptoms lateral canthotomy with cantholysis is indicated. This is recommended to be carried out within two hours. The condition is rare. == References ==