For the long term aim to develop a visual cortical prosthesis, optogenetic stimulation of primary visual cortex (V1) provides a more specific alternative to electrical stimulation. However, adoption of optogenetic techniques from rodents to macaques as an intermediate step towards humans has proven to be challenging. Here we present prelimnary results, directly comparing effects obtained from optogenetic vs electrical stimulation of macaque V1.We injected AAV9-CamKIIa-ChrimsonR-mScarlet-KV2.1 into macaque V1 under electrophysiological guidance. We first investigated neural activity in response to 300 ms, 0.2 mW of optogenetic stimulation and compared it to neural activity evoked by a full-field visual stimulus. Electrophysiological analysis showed a strong, short latency response in multi-unit activity (MUA), predominantly in V1 superficial layers. Effects in local field potential (LFP) power were more widely distributed with both positive as well as negative responses. To assess phosphene perception, we studied saccadic inhibition, which refers to a short-lived transient cessation of saccade generation occurring within 100ms following a visual stimulus (Khademi et al, 2023). Our results show that microsaccades post-stimulus are inhibited under visual and electrical microstimulation (100 ms train duration, <160 uA, frequency range 100-1000 Hz) conditions, whereas preliminary results from optogenetic stimulation indicate only a slight reduction in microsaccadic inhibition. These findings are consistent with explicit behavioural report measures. Taken together, our preliminary results from one monkey illustrate the need to better understand the relationship between neural activation and phosphene perception. Despite its caveats, V1 electrical stimulation more readily elicits visual phosphenes compared to optogenetics.