Doctor Neumeister tests the retina and optic nerve function based on the evaluation of spectral properties of the pupil light reflex.
Conditions that frequently cause loss of vision and pupil light reflex abnormalities include:

• Sudden acquired retinal degeneration (SARD)
• Immune-mediated steroid-responsive retinitis
• Retinal degeneration (hereditary)
• Chorio-retinitis/retinitis
• Retinal detachment
• Glaucoma
• Optic neuritis / meningitis; pituitary tumor, chiasmal tumor
• Brain tumor / visual cortex damage
• Ophthalmoplegia interna / external
• Retinal disease

Over 40 breeds of dogs and cats possess the predisposition to glaucoma. It is a condition that causes damage to the eye’s optic nerve and gets worse over time. It is often associated with a buildup of pressure inside the eye. The increased pressure, called intraocular pressure, can damage the optic nerve, which transmits images to the brain. Without treatment, glaucoma can cause total permanent blindness within a few years.

Using a precision electronic tonometer, Dr. Neumeister can monitor/screen the IOP (Intraocular pressure) or glaucoma. Source: (1),(2)

Also providing diagnosis of eye-(ocular) diseases, with color-based pupil testing as well as intraocular pressure measuring.

Sources:

 (1) http://www.vin.com/doc/?id=542255
(2) http://www.webmd.com/eye-health/glaucoma-eyes