Shortest acting mydriatic is -

Ans. is 'c' i.e., Tropicamide Salient features of common cvcloplegic and mydriatic drugsSL Name of no. the drugAge of the patient when indicatedDosage of instillationPeak effectTime of performing retinoscopyDuration of actionPeriod of Postcycloplegic testTonus allowance1. Atropine sulphate (1% ointment)< 5 yearTDSx3 day2-3 days4th day10-20 daysAfter 3 weeks of retinoscopyID2. Homatropine hydrobromide (2% drops)5-8 yearsOne drop every 10 min. for 6 times60-90 min.After 90 min. of instillation of first drop48-72 hoursAfter 3 days of retinoscopy0.5D3. Cyclopentolale hydrochloride (1% drops)8-20 yearsOne drop every 15 min. for 3 times80-90 min.After 90 min. of instillation of first drop6-18 hoursAfter 3 days of retinoscopy0.75D4. Tropicamide (0.5%, 1% drops)Not used as cycloplegie for retinoscopy; used only as mydriaticOne drop every 15 min. for 3 to 4 times20-40 min. 4-6 hours 5. Phenyephrine(5%, 10% drops)Used only as mydriatic alone or in combination with tropicamideOne drop every 15 min. for 3 to 4 times30-40 min. 4-6 hours