Ophthalmic drugs 

Learning objectives: Learn about the drugs that are instilled or applied on eyes, their classification and mechanism of action

Anatomy of the eye 

Anatomy of the eye

Key Parts of the Eye

Part Function/Description

Iris Colorful part that controls light entry

Cornea Clear outer part directing images into the eye 

Lens Focuses images onto the retina

Pupil Dark center of the eye

Retina Lining at the back of the eye

Fovea Part of the retina containing only cones

Photoreceptors: Cones and Rods

• Cones are sensitive to color and detail, while rods are sensitive to low light.

• Mnemonic for cones: 'You see these when you pass an accident on the road.'

• Mnemonic for rods: 'What you use when you go fishing.'

Signal Processing in the Retina

• Ganglion cells receive signals from bipolar cells, crucial for transmitting visual information to the brain.

• Bipolar cells first receive messages from rods and cones, acting as intermediaries.

• Mnemonic for ganglion cells: 'A pride of lions' and for bipolar cells: 'A bear in cold climates.'

Color Vision Theories

Opponent Process Theory

• This theory states that color perception is controlled by opposing pairs: red-green, blue-yellow.

• Mnemonic: 'Cones in a boxing ring with one knocked out.'

• Only one color from each pair can be perceived at a time.

Trichromatic Theory

• This theory posits that color vision is based on three types of cones sensitive to red, green, and blue.

• Mnemonic: 'Tricycles and a blender' to remember the blending of colors.

• The combination of signals from these cones allows for the perception of a wide range of colors.

[Reference: https://quizlet.com/study-guides/mnemonic-devices-for-eye-and-ear-anatomy-17886793-886d-406e-9988-7e9daf17f7db]

Practice questions

Further reading

• Antibiotic Classes in 7 minutes

• A Brief Overview of Classes of Antibiotics

•