netFormulary Isle of Wight NHS
 Formulary Chapter 11: Eye - Full Section

Calculating Quantities of Eye Drops:

[The following is a guide and will depend on issues such as dexterity and accuracy which should be assessed at point of prescribing.]

It is generally accepted that 5ml = 100 drops & 10ml = 200 drops etc. (Ranges can vary and can be 100-130 for 5 ml when allowing for overage) 

General Advice:

  • The eye typically holds 1 drop. Instruction such as 1-2 drops can be interpreted as wasteful as the second drop washes out the first. Should multiple drops be required or multiple products it is advised that the individual waits 5-10mins between drops to allow the first to work.
  • Where possible specify which eye the drops are to be used in. This helps patients compliance and adherence, but also helps when transferring information between services and care settings.
  • If eye ointment is being used along with a drop then patients should be advised to use drops first and then 5-10 minutes later apply ointment. Most ointments will temporarily blur vision and care should be taken during this time.
  • Check if the patient wears contact lenses. The majority of eye preparations require lenses to be removed whilst using them.
  • Administration aids are available should dexterity/ accuracy be an issue.
  • Some preparations may cause stinging/irritation on application, this should ease quickly. However should patients find this is not manageable, is not improving, or getting worse then a review will be needed to find a more suitable option
 Useful Links
Numbers in brackets indicate counts of (Formulary items, Non Formulary items)
11.03 Anti-infective eye preparations (0,0)
11.03.01 Antibacterials (5,0)
11.03.03 Antivirals (1,0)
11.04 Corticosteroids and other anti-inflammatory preparations (0,0)
11.04.01 Corticosteroids (9,0)
11.04.02 Other anti-inflammatory preparations (2,0)
11.05 Mydriatics and cycloplegics (0,0)
Antimuscarinics (4,0)
Sympathomimetics (3,0)
11.06 Treatment of glaucoma (0,0)
Beta-blockers (1,0)
Prostaglandin analogues (8,0)
Sympathomimetics (2,0)
Carbonic anhydrase inhibitors and systemic drugs (6,0)
Miotics (1,0)
11.07 Local anaesthetics (5,0)
11.08 Miscellaneous ophthalmic preparations (1,0)
11.08.01 Tear deficiency, ocular lubricants, and astringents (9,0)
11.08.02 Ocular diagnostic and peri-operative preparations and photodynamic treatment (0,0)
Ocular diagnostic preparations (2,0)
Ocular peri-operative drugs (4,0)
Subfoveal choroidal neovascularisation (3,0)
Vitreomacular traction (1,0)