COMMUNICATIONS RETINAL CYSTS ANDRETINOSCHISIS* BY C. G. KEITH DepartmentofPathology, Institute ofOphthalmology, University ofLondon SINCE the term retinoschisis came into commonophthalmological parlance, it has oftenbeenusedas thoughthe conditionwereadefinite entity, differing fromretinal cysts bythe process byWhichit arose.
The definition of imperative is something that has authority or is absolutely necessary. 1  An example of imperative is the power that a government has over its people.  An example of imperative is the decision to give a cesarean in a breach birth.
In English, the imperative is formed using the bare infinitive form of the verb (see English verbs for more details). This is usually also the same as the second-person present indicative form, except in the case of the verb to be, where the imperative is be while the indicative is are.