"Scleritis: presentations, disease associations and management". Postgrad Med J. 88 (1046): 713–18. doi:10.1136/postgradmedj-2011-130282. [en.wikipedia.org]

• Irritability

  Severe pain[edit] Those with conjunctivitis may report mild irritation or scratchiness, but never extreme pain, which is an indicator of more serious disease such as keratitis, corneal ulceration, iridocyclitis, or acute glaucoma. [en.wikipedia.org]

Management includes assessing whether emergency action (including referral) is needed, or whether treatment can be accomplished without additional resources. [en.wikipedia.org]