Opportunistic perception verbs (‘see’, ‘hear’, as opposed to explorative perception verbs, ‘look’, ‘listen’) express the opportunity for perception and are condition-oriented (exposure, i.e. the perceiver’s exposure to a stimulus), not participant-oriented, in their aspectual structure. The Baltic languages, as other languages in Central, East, and Northern Europe, have specific perception verbs, which are a subtype of opportunistic perception verbs, for the expression of restricted exposure. The lexical character of specificity in Baltic—unlike Russian where it is integrated into a rigid grammatical aspect system—is more favorable for uncovering the underlying semantic factors of specificity, which differ across perceptual systems. Restrictedness of exposure is a scale rather than a dichotomy, and cross-linguistic comparison in parallel texts reveals that specificity is a scale with much variation as to where the borderline between specific and non-specific perception verbs is drawn in the languages of the area. Obscured perception verbs, which emphasize difficulty in discrimination, are another set of condition-oriented perception verbs in Baltic and Russian and are closely related to specific verbs synchronically and diachronically. 
 This paper describes non-specific, specific, and obscured perception verbs in the Baltic languages and attempts to capture their variability within six dimensions (morphology, area, diachrony, specificity, modality, obscured verbs). A precondition for this endeavor is a critique of earlier approaches to the semantics of perception verbs. Nine major biases are identified (nominalism, physiology, discrete features, vision, paradigmatic modelling, aspectual event types, dual nature models, participant orientation, and viewing activity as control). In developing an alternative, the approach greatly profits from Gibson’s ecological psychology and Rock’s theory of indirect perception.